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Cracking the code-ing sequence for Parkinson’s disease

Jansen, I.E.

2017

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citation for published version (APA)

Jansen, I. E. (2017). Cracking the code-ing sequence for Parkinson’s disease.

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CHAPTER 1

General introduction

to Parkinson’s disease

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1

WĂƌŬŝŶƐŽŶ͛ƐĚŝƐĞĂƐĞ;WͿŝƐĂƉƌŽŐƌĞƐƐŝǀĞŶĞƵƌŽĚĞŐĞŶĞƌĂƟǀĞĚŝƐŽƌĚĞƌ͕ǁŚŝĐŚŝƐƚǇƉŝĐĂůůǇ

ƌĞĐŽŐŶŝǌĞĚ ďǇ ƚŚĞ ƉƵďůŝĐ ĂƐ ƚŚĞ ŵŽǀĞŵĞŶƚ ĚŝƐĞĂƐĞ ŽĨ ƚŚĞ ĞůĚĞƌůǇ͘ /ŶĚĞĞĚ ƚŚĞ ƌŝƐŬ ƚŽ develop PD increases with age, but PD is also diagnosed in younger individuals. The prevalence ranges from 0.04% for the age group between 40 and 49 years, to 1.9% for

individuals over 80 years.1_{WŝƐĂĐŽŵƉůĞǆĚŝƐŽƌĚĞƌ͕ǁŚŝĐŚŝƐƌĞŇĞĐƚĞĚŝŶƚŚĞǀĂƌŝĞƚǇŽĨ}

ƐǇŵƉƚŽŵƐ͕ƉĂƚŚŽůŽŐŝĞƐĂŶĚŐĞŶĞƟĐĐĂƵƐĞƐ͘dŚĞƐĞŚĞƚĞƌŽŐĞŶĞŽƵƐĨĞĂƚƵƌĞƐĐŽŵƉůŝĐĂƚĞƚŚĞ ĚĞǀĞůŽƉŵĞŶƚŽĨĚŝƐĞĂƐĞƌĞǀĞƌƐŝŶŐƚƌĞĂƚŵĞŶƚ͕ǁŚŝĐŚŝƐƚŚĞƵůƟŵĂƚĞŐŽĂůŽĨƚŚĞWƌĞƐĞĂƌĐŚ ĮĞůĚ͘

Heterogeneous features of Parkinson’s disease

ůŝŶŝĐĂůƐǇŵƉƚŽŵƐĐŚĂƌĂĐƚĞƌŝǌŝŶŐWĂƌĞŚĞƚĞƌŽŐĞŶĞŽƵƐĂŶĚĞŶĐŽŵƉĂƐƐďŽƚŚƚŚĞĐůĂƐƐŝĐĂů ŵŽƚŽƌ ƐǇŵƉƚŽŵƐ ĂŶĚ ƚŚĞ ŵŽƌĞ ƌĞĐĞŶƚůǇ ƌĞĐŽŐŶŝǌĞĚ ŶŽŶͲŵŽƚŽƌ ƐǇŵƉƚŽŵƐ͕ ǁŚŝĐŚ frequently precede the motor features by a decade. The motor symptoms consist of ďƌĂĚǇŬŝŶĞƐŝĂ;ĞǆƚƌĞŵĞƐůŽǁŶĞƐƐŽĨŵŽǀĞŵĞŶƚƐĂŶĚƌĞŇĞǆĞƐͿ͕ƌŝŐŝĚŝƚǇ;ƐƟīŶĞƐƐͿ͕ƌĞƐƟŶŐ

tremor and postural disturbances.2_{Based on the motor symptoms, two clinical subtypes}

are suggested that separate a tremor-dominant type and a non-tremor-dominant type.3

dŚĞĮƌƐƚƐƵďƚǇƉĞĐŽŵĞƐǁŝƚŚĂƐůŽǁĞƌƉƌŽŐƌĞƐƐŝŽŶƌĂƚĞĂŶĚůŝƩůĞĨƵŶĐƟŽŶĂůŝŵƉĂŝƌŵĞŶƚ ĐŽŵƉĂƌĞĚ ƚŽ ƚŚĞ ŶŽŶͲƚƌĞŵŽƌͲĚŽŵŝŶĂŶƚ ƚǇƉĞ͘ dŚĞ ƐĞĐŽŶĚ ƚǇƉĞ ŝƐ ŵĂŝŶůǇ ĚĞĮŶĞĚ ďǇ ƌŝŐŝĚŝƚǇ ĂŶĚ ƉŽƐƚƵƌĂů ĚĞƚĞƌŝŽƌĂƟŽŶƐ͘ /Ŷ ĂĚĚŝƟŽŶ ƚŽ ƚŚĞ ŵŽƚŽƌ ƐǇŵƉƚŽŵƐ͕ ǀĂƌŝŽƵƐ ŶŽŶͲ ŵŽƚŽƌƐǇŵƉƚŽŵƐŚŝŶĚĞƌƚŚĞƋƵĂůŝƚǇŽĨƚŚĞƉĂƟĞŶƚ͛ƐůŝĨĞ͘4_{dŚĞŶŽŶͲŵŽƚŽƌƐǇŵƉƚŽŵƐŽŌĞŶ} ƉƌĞƐĞŶƚƚŚĞŵƐĞůǀĞƐďĞĨŽƌĞĚŝĂŐŶŽƐŝƐ͕ĂŶĚĂƌĞŝŶŝƟĂůůǇŶŽƚƐƵŐŐĞƐƟǀĞĨŽƌĂĚŝĂŐŶŽƐŝƐŽĨW͘ WƌŽĚƌŽŵĂůĨĞĂƚƵƌĞƐĂƌĞĐŽŶƐƟƉĂƟŽŶ͕ƐůĞĞƉĚŝƐŽƌĚĞƌƐ͕ŽůĨĂĐƚŽƌǇĚǇƐĨƵŶĐƟŽŶĂŶĚĚĞƉƌĞƐƐŝŽŶ͕ ǁŚŝĐŚĐŽŶƟŶƵĞƚŽĞǀŽůǀĞŽŶĐĞƚŚĞĚŝĂŐŶŽƐŝƐŚĂƐďĞĞŶĚĞƚĞƌŵŝŶĞĚ͘5_{ĚĚŝƟŽŶĂůŶŽŶͲŵŽƚŽƌ} ƐǇŵƉƚŽŵƐƉŽƐƚĚŝĂŐŶŽƐŝƐŝŶĐůƵĚĞĨĂƟŐƵĞ͕ůŽǁďůŽŽĚƉƌĞƐƐƵƌĞ͕ƵƌŝŶĂƌǇƐǇŵƉƚŽŵƐĂŶĚŵŝůĚ

ĐŽŐŶŝƟǀĞŝŵƉĂŝƌŵĞŶƚƚŚĂƚƉŽƚĞŶƟĂůůǇƉƌŽŐƌĞƐƐĞƐŝŶƚŽĚĞŵĞŶƟĂ͘3,6_{The premotor phase}

ranges from years to decades.7,8_{ǆƚĞŶƐŝǀĞ ƌĞƐĞĂƌĐŚ ŽĨ ƚŚĞ ƉƌŽĚƌŽŵĂů ƉĞƌŝŽĚ ŚĂƐ ƚŚĞ}

ƉŽƚĞŶƟĂůƚŽŝĚĞŶƟĨǇƉƌŽĚƌŽŵĂůďŝŽŵĂƌŬĞƌƐƚŚĂƚĐŽƵůĚĞŶĂďůĞƚŚĞWĚŝĂŐŶŽƐŝƐŝŶĂŶĞĂƌůŝĞƌ ƐƚĂŐĞďĞĨŽƌĞƚŚĞŽŶƐĞƚŽĨŵŽƚŽƌƐǇŵƉƚŽŵƐ͕ǁŚŝĐŚŵŝŐŚƚďĞďĞŶĞĮĐŝĂůĨŽƌƚƌĞĂƚŵĞŶƚŽĨƚŚĞ

disease.5

Besides the division of clinical subtypes based on motor symptoms, other ƐƵďƚǇƉĞƐĂƌĞďĂƐĞĚŽŶƚŚĞĂŐĞŽĨŽŶƐĞƚ͘WƉĂƟĞŶƚƐǁŝƚŚĂǇŽƵŶŐŽŶƐĞƚ;ĐƵƚŽīƌĂŶŐĞƐ

from 40 to 55 years9-11_{Ϳ ĐŽŵƉƌŝƐĞ ďĞƚǁĞĞŶ ϱй ĂŶĚ ϭϬй ŽĨ ƚŚĞ W ƉŽƉƵůĂƟŽŶ͘}10,11_The

ŵĂŝŶŽǀĞƌĂůůĚŝīĞƌĞŶĐĞďĞƚǁĞĞŶǇŽƵŶŐͲŽŶƐĞƚWĂƌŬŝŶƐŽŶ͛ƐĚŝƐĞĂƐĞ;zKWͿĂŶĚƚǇƉŝĐĂůW

ŝƐ ƚŚĞ ƐůŽǁĞƌ ĚŝƐĞĂƐĞ ƉƌŽŐƌĞƐƐŝŽŶ ŝŶ ƚŚĞ ǇŽƵŶŐĞƌ ƉĂƟĞŶƚƐ͘12,13_{&ƵƌƚŚĞƌŵŽƌĞ͕ zKW ŚĂƐ}

ďĞĞŶĂƐƐŽĐŝĂƚĞĚǁŝƚŚŝŶĐƌĞĂƐĞĚůĞǀŽĚŽƉĂͲŝŶĚƵĐĞĚŵŽƚŽƌĐŽŵƉůŝĐĂƟŽŶƐ14_{, earlier motor}

impairments (e.g. dyskinesia and dystonia)14,15_{, increased risk of psychiatric symptoms}4,16-18

ĂŶĚůĞƐƐĐŽŐŶŝƟǀĞĚĞĐůŝŶĞ15,19_{͘ƐĚŝƐƟŶĐƚŽƵƚĐŽŵĞƐŚĂǀĞďĞĞŶƌĞƉŽƌƚĞĚŽŶĚŝīĞƌĞŶĐĞƐ}

ŝŶŶŽŶͲŵŽƚŽƌƐǇŵƉƚŽŵƐďĞƚǁĞĞŶzKWĂŶĚĐůĂƐƐŝĐĂůW͕11,20_{ŵŽƌĞĞǆƚĞŶƐŝǀĞƌĞƐĞĂƌĐŚŝƐ}

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1

dǁŽ ŵĂŝŶ ƉĂƚŚŽůŽŐŝĐĂů ŚĂůůŵĂƌŬƐ ĐŚĂƌĂĐƚĞƌŝǌĞ W͘ dŚĞ ůŽƐƐ ŽĨ ĚŽƉĂŵŝŶĞƌŐŝĐ ŶĞƵƌŽŶƐ ŝŶ ƚŚĞ ^ƵďƐƚĂŶƟĂ EŝŐƌĂ ƉĂƌƐ ĐŽŵƉĂĐƚĂ ;^EƉĐͿ ǁĂƐ ƚŚĞ ĮƌƐƚ ŵĂĐƌŽƐĐŽƉŝĐ

pathological feature observed for PD.21,22_{EĞƵƌŽĚĞŐĞŶĞƌĂƟŽŶŝŶƚŚŝƐƉĂƌƚŽĨƚŚĞŵŝĚďƌĂŝŶ}

ƌĞƐƵůƚƐŝŶďĂƐĂůŐĂŶŐůŝĂŝŵƉĂŝƌŵĞŶƚƐĐĂƵƐŝŶŐƚŚĞŵŽƚŽƌƐǇŵƉƚŽŵƐŝŶWƉĂƟĞŶƚƐ͘23,24_At

the moment of clinical onset, more than 50% of the dopaminergic neurons in the SNpc

are degenerated.25,26_{Although neuronal loss is most prominent in the SNpc, other brain}

ƌĞŐŝŽŶƐĂƌĞĂůƐŽĂīĞĐƚĞĚƐƵĐŚĂƐƚŚĞŐůŽƐƐŽƉŚĂƌǇŶŐĞĂůĂŶĚǀĂŐĂůŶĞƌǀĞƐ͕ŽůĨĂĐƚŽƌǇďƵůď͕

ůŽĐƵƐ ĐŽĞƌƵůĞƵƐ͕ ŵĞĚƵůůĂ͕ ŵĞƐŽĐŽƌƚĞǆ ĂŶĚ ŶĞŽĐŽƌƚĞǆ͘27_{dŚĞ ŶĞƵƌŽŶĂů ĚĞŐĞŶĞƌĂƟŽŶ ŝŶ}

these regions is accompanied by the second microscopic pathological hallmark: Lewy bodies.

Lewy bodies (LB) are abnormal protein aggregates observed in the cytoplasm of

ŶĞƵƌŽŶĂůĐĞůůƐŝŶWƉĂƟĞŶƚƐ͘28_{>ĂƌĞĂĐŚĂƌĂĐƚĞƌŝƐƟĐƉĂƚŚŽůŽŐŝĐĨĞĂƚƵƌĞŽĨW͕ĂůƚŚŽƵŐŚ}

Ă ƐŵĂůů ƉƌŽƉŽƌƟŽŶ ŽĨ ƉŽƐƚͲŵŽƌƚĞŵ ďƌĂŝŶ ƟƐƐƵĞ ŽĨ W ƉĂƟĞŶƚƐ ůĂĐŬ >ͲƉĂƚŚŽůŽŐǇ ;Ğ͘Ő͘

ŵƵƚĂƟŽŶĐĂƌƌŝĞƌƐŽĨƚŚĞƉĂƌŬŝŶƐŽŶŝƐŵŐĞŶĞparkin29,30_{), ƐƵŐŐĞƐƟŶŐĂĚĚŝƟŽŶĂůƵŶĚŝƐĐŽǀĞƌĞĚ}

forms of protein aggregates. dŚĞƉƌŝŵĂƌǇĐŽŵƉŽŶĞŶƚŽĨ>ŝƐɲͲƐǇŶƵĐůĞŝŶ͕ǁŚŝĐŚŝƐĂƐŵĂůů ƉƌŽƚĞŝŶ;ϭϰϬĂŵŝŶŽĂĐŝĚƌĞƐŝĚƵĞƐǁĞŝŐŚƟŶŐΕϰϬŬͿĞŶĐŽĚĞĚďǇ SNCA that is mainly ĞǆƉƌĞƐƐĞĚ ŝŶ ďƌĂŝŶ ĂŶĚ͕ ŝŶ ŚĞĂůƚŚǇ ƐƚĂƚĞ͕ ŚĂƐ ŝƚƐ ƌŽůĞ ŝŶ ƐǇŶĂƉƟĐ ĨƵŶĐƟŽŶ ĂŶĚ ůŽĐĂůŝǌĞƐ

ƚŽƚŚĞƉƌĞƐǇŶĂƉƟĐƚĞƌŵŝŶĂůƐ͘31_{/ŶĐƌĞĂƐĞĚůĞǀĞůƐŽĨɲͲƐǇŶƵĐůĞŝŶĐĂƵƐĞƐĂŵŝŐƌĂƟŽŶŽĨƚŚĞ}

protein to the cytoplasm and generates misfolded protein inclusions in the cell body (Lewy

ďŽĚŝĞƐͿĂŶĚŝŶĂǆŽŶƐŽƌĚĞŶĚƌŝƚĞƐ;>ĞǁǇŶĞƵƌŝƚĞƐͿ͘32_{ŝƐƟŶĐƚĂŐŐƌĞŐĂƚĞƚǇƉĞƐĞǆŝƐƚ͕ƌĂŶŐŝŶŐ} ĨƌŽŵƚŚƌĞĂĚͲůŝŬĞɲͲƐǇŶƵĐůĞŝŶƐƚƌƵĐƚƵƌĞƐƚŚƌŽƵŐŚƐŽůƵďůĞŵŽŶŽŵĞƌͲĐŽŵƉŽƐŝŶŐŽůŝŐŽŵĞƌƐ͘33 ůƚŚŽƵŐŚƚŚĞƚƌĂĚŝƟŽŶĂůƚŚĞŽƌǇǀŝĞǁĞĚƚŚĞůĂƌŐĞŝŶƐŽůƵďůĞĮďƌŝůůĂƌǇƉƌŽƚĞŝŶĂŐŐƌĞŐĂƚĞƐĂƐ ƚŚĞƚŽǆŝĐĐŽŵƉŽŶĞŶƚƐŝŶĚƵĐŝŶŐŶĞƵƌŽĚĞŐĞŶĞƌĂƟŽŶ͕ŵŽƌĞƌĞĐĞŶƚƌĞƐĞĂƌĐŚƉƌŽƉŽƐĞƐƚŚĂƚ ƚŚĞƐŵĂůůĞƌƐŽůƵďůĞŽůŝŐŽŵĞƌƐĂƌĞƚŚĞƚǇƉĞĐĂƵƐŝŶŐĐǇƚŽƚŽǆŝĐŝƚǇ͘34_{It is currently unknown} ǁŚŝĐŚƐƉĞĐŝĮĐƚǇƉĞŽĨɲͲƐǇŶƵĐůĞŝŶĂŐŐƌĞŐĂƚĞƐĂƌĞƚŚĞƚŽǆŝĐƐƉĞĐŝĞƐ͘ ɲͲƐǇŶƵĐůĞŝŶĂŐŐƌĞŐĂƚĞƐĂƌĞŽďƐĞƌǀĞĚŝŶƚŚĞ^EƉĐ͕ďƵƚĂƌĞĂůƐŽƉƌĞƐĞŶƚŝŶŽƚŚĞƌ

brain regions lacking macroscopic changes.35_{ZĞƐĞĂƌĐŚŽŶƚŚĞĚŝƐƚƌŝďƵƟŽŶŽĨ>ƉĂƚŚŽůŽŐǇ}

ƚŚƌŽƵŐŚŽƵƚƚŚĞďƌĂŝŶƉƌŽƉŽƐĞĚϲĚŝīĞƌĞŶƚƐƚĂŐĞƐŽĨŶĞƵƌŽĚĞŐĞŶĞƌĂƟŽŶĨŽůůŽǁŝŶŐĂƐƉĞĐŝĮĐ

anatomical route, currently well known as Braak staging.27_{dŚĞĮƌƐƚŝŶĐůƵƐŝŽŶƐĂƉƉĞĂƌŝŶ}

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ĐŽŶƚƌŝďƵƚĞƐƚŽĐŽŐŶŝƟǀĞŝŵƉĂŝƌŵĞŶƚŽďƐĞƌǀĞĚŝŶƚŚĞůĂƚĞƌƉŚĂƐĞƐŽĨƚŚĞĐůŝŶŝĐĂůĚŝƐĞĂƐĞ progression.36,37 ZĞĐĞŶƚ ƐƚƵĚŝĞƐ ŚĂǀĞ ŝŶǀĞƐƟŐĂƚĞĚ ƚŚĞ ƉĂƚŚŽůŽŐŝĐĂů ƉƌŽŐƌĞƐƐŝŽŶ ĨƌŽŵ ŶĞƵƌŽŶ ƚŽ ŶĞƵƌŽŶŝŶĚŝƐƟŶĐƚďƌĂŝŶƌĞŐŝŽŶƐ͘dŚĞĮƌƐƚŚŝŶƚŽƌŝŐŝŶĂƚĞƐĨƌŽŵŽďƐĞƌǀĂƟŽŶƐŽĨƌĞƐĞĂƌĐŚ ƚƌĂŶƐƉůĂŶƟŶŐŚĞĂůƚŚǇĨĞƚĂůĚŽƉĂŵŝŶĞĐĞůůƐŝŶƚŽƚŚĞƐƚƌŝĂƚƵŵŽĨWƉĂƟĞŶƚƐ͘38,39_Pathological ĞǆĂŵŝŶĂƟŽŶŽĨƚŚĞƐĞďƌĂŝŶƐĂŌĞƌŽŶĞŽƌƚǁŽĚĞĐĂĚĞƐƌĞǀĞĂůĞĚƚŚĂƚƚŚĞŐƌĂŌĞĚŶĞƵƌŽŶƐ ĂůƐŽĚĞǀĞůŽƉĞĚ>ƉĂƚŚŽůŽŐǇ͕ƐƵŐŐĞƐƟŶŐƉƌŝŽŶͲůŝŬĞƚƌĂŶƐŵŝƐƐŝŽŶŽĨɲͲƐǇŶƵĐůĞŝŶŝŶĐůƵƐŝŽŶƐ͘ dŚŝƐ ŚǇƉŽƚŚĞƐŝƐ ůĞĚ ƚŽ ŵƵůƟƉůĞ ŝŶͲǀŝǀŽ ŵŽĚĞůƐ ƐŚŽǁŝŶŐ ƚŚĞ ƚƌĂŶƐŵŝƐƐŝŽŶ ŽĨ ŝŶũĞĐƚĞĚ ɲͲƐǇŶƵĐůĞŝŶ ĮďƌŝůƐ ǁŝƚŚŝŶ ǀĂƌŝŽƵƐ ďƌĂŝŶ ƌĞŐŝŽŶƐ ƚŽ ƉƌĞǀŝŽƵƐůǇ ƵŶĂīĞĐƚĞĚ ŽƚŚĞƌ ďƌĂŝŶ

regions in transgenic SNCA or wildtype mice.40-42_{&ƵƌƚŚĞƌŵŽƌĞ͕ Ă ŵĂĐĂƋƵĞ ŵŽĚĞů͕ Ă}

ƐƉĞĐŝĞƐĐůŽƐĞƌƌĞůĂƚĞĚƚŽŚƵŵĂŶ͕ƐŚŽǁĞĚƐŝŵŝůĂƌĮŶĚŝŶŐƐďǇŝŶũĞĐƟŶŐɲͲƐǇŶƵĐůĞŝŶŝŶĐůƵƐŝŽŶ

ĨƌŽŵ ƉŽƐƚŵŽƌƚĞŵ ďƌĂŝŶ ƟƐƐƵĞ ŽĨ W ƉĂƟĞŶƚƐ ŝŶƚŽ ƚŚĞ ^EƉĐ Žƌ ƐƚƌŝĂƚƵŵ ŽĨ ŵĂĐĂƋƵĞ͘43

WƌŽŐƌĞƐƐŝǀĞŶŝŐƌŽƐƚƌŝĂƚĂůŶĞƵƌŽĚĞŐĞŶĞƌĂƟŽŶƵƉŽŶ>ĞǆƚƌĂĐƚƐŝŶŽĐƵůĂƟŽŶƐǁĂƐŽďƐĞƌǀĞĚ͘ Although these animal models support the hypothesis of a prion-like transmission of ɲͲƐǇŶƵĐůĞŝŶĂŐŐƌĞŐĂƚĞƐ͕ŶŽǀĞůƚĞĐŚŶŝƋƵĞƐƌĞůǇŝŶŐŽŶĚŝƌĞĐƚŽďƐĞƌǀĂƟŽŶƐŽĨƚŚĞƚŽƚĂůƟŵĞͲ ĐŽƵƌƐĞŽĨƉƌŽŐƌĞƐƐŝŽŶŝŶWƉĂƟĞŶƚƐ;ŝŶƐƚĞĂĚŽĨƐŶĂƉƐŚŽƚƐŝŶĂŶŝŵĂůŵŽĚĞůƐͿĂƌĞƌĞƋƵŝƌĞĚ ƚŽĂůůŽǁĚĞĮŶŝƚĞĐŽŶĐůƵƐŝŽŶƐĂďŽƵƚƚŚŝƐƚŽƉŝĐ͘44 ŝĂŐŶŽƐŝƐŽĨWŝƐƉƌĞĚŽŵŝŶĂŶƚůǇďĂƐĞĚŽŶĐůŝŶŝĐĂůƐǇŵƉƚŽŵƐ͕ďƵƚŽŶůǇĚĞĮŶŝƚĞ ĂŌĞƌƉĂƚŚŽůŽŐŝĐĂůĐŽŶĮƌŵĂƟŽŶďĂƐĞĚŽŶƉŽƐƚͲŵŽƌƚĞŵďƌĂŝŶƟƐƐƵĞ͘dŚĞĚŝĂŐŶŽƐƟĐĐƌŝƚĞƌŝĂ ŚĂǀĞƌĞĐĞŶƚůǇďĞĞŶƵƉĚĂƚĞĚƌĞƐƵůƟŶŐŝŶƚŚĞDŽǀĞŵĞŶƚŝƐŽƌĚĞƌ^ŽĐŝĞƚǇůŝŶŝĐĂůŝĂŐŶŽƐƟĐ

Criteria for Parkinson’s Disease.45_{ůƚŚŽƵŐŚƚŚĞŵĂŝŶĚŝĂŐŶŽƐƟĐĐƌŝƚĞƌŝŽŶĐŽŶƟŶƵĞƐƚŽďĞ}

ƚŚĞŵŽƚŽƌƐǇŵƉƚŽŵƐ͕ƚŚĞŶŽŶͲŵŽƚŽƌƐǇŵƉƚŽŵƐĂƌĞŝŶĐƌĞĂƐŝŶŐůǇĞŵƉŚĂƐŝǌĞĚ͘,ŽǁĞǀĞƌ͕ ĨŽƌƚŚŝƐƚŚĞƐŝƐƚŚĞĞĂƌůŝĞƌĐƌŝƚĞƌŝĂǁĞƌĞƵƐĞĚĨŽƌƚŚĞĚŝĂŐŶŽƐŝƐŽĨWƉĂƟĞŶƚƐ͘hŶƟůKĐƚŽďĞƌ ϮϬϭϱ͕ƚŚĞŐĞŶĞƌĂůĐŽŶƐĞŶƐƵƐǁĂƐƚŽƵƐĞƚŚĞh<WĂƌŬŝŶƐŽŶ͛ƐŝƐĞĂƐĞ^ŽĐŝĞƚǇƌĂŝŶĂŶŬ

criteria2_{͕ ŽĨ ǁŚŝĐŚ ƚŚĞ ŚŝŐŚĞƐƚ ƐĞŶƐŝƟǀŝƚǇ ƌĂƚĞ ŝƐ ĞƐƟŵĂƚĞĚ ƚŽ ďĞ Ăƚ ϵϬй͘}46_{dŚĞ ƉĂƟĞŶƚ}

should present with bradykinesia and one other motor symptom, including mascular ƌŝŐŝĚŝƚǇ͕ ƌĞƐƟŶŐ ƚƌĞŵŽƌ Žƌ ƉŽƐƚƵƌĂů ŝŶƐƚĂďŝůŝƚǇ͘ ƌĞƐƉŽŶƐĞ ƚŽ ůĞǀŽĚŽƉĂ͕ Ă ĚƌƵŐ ƚŚĂƚ

increases the dopamine level, strengthens the diagnosis.47_{KƚŚĞƌĚŝīĞƌĞŶƟĂůĚŝĂŐŶŽƐĞƐ}

ƐŚŽƵůĚ ďĞ ĞǆĐůƵĚĞĚ ĐŽŶƐŝĚĞƌŝŶŐ ĚŝƐĞĂƐĞƐ ƐƵĐŚ ĂƐ ŵƵůƟƉůĞ ƐǇƐƚĞŵ ĂƚƌŽƉŚǇ͕ ƉƌŽŐƌĞƐƐŝǀĞ ƐƵƉƌĂŶƵĐůĞĂƌƉĂůƐǇ͕ĐŽƌƟĐŽďĂƐĂůĚĞŐĞŶĞƌĂƟŽŶ͕ĞƐƐĞŶƟĂůƚƌĞŵŽƌ͕ůǌŚĞŝŵĞƌ͛ƐĚŝƐĞĂƐĞĂŶĚ ǀĂƐĐƵůĂƌƉĂƌŬŝŶƐŽŶƐŝŵ͘dŚĞůĂƩĞƌƚŚƌĞĞĚŝƐĞĂƐĞƐĂƌĞŶŽƚĐĂƵƐĞĚďǇĂůŽƐƐŽĨŶĞƵƌŽŶƐŝŶƚŚĞ SNpc.

Positron emission tomography (PET) and single photon emission computed ƚŽŵŽŐƌĂƉŚǇ ;^WdͿ ĂƌĞ ŝŵĂŐŝŶŐ ƚĞĐŚŶŝƋƵĞƐ ƚŚĂƚ ŚĞůƉ ĚŝīĞƌĞŶƟĂƚĞ ďĞƚǁĞĞŶ W ĂŶĚ ĚŝƐĞĂƐĞƐŶŽƚƌĞůĂƚĞĚƚŽ^EƉĐĚĞŐĞŶĞƌĂƟŽŶ͕ĂƐƚŚĞǇŵĞĂƐƵƌĞƚŚĞĚĞŶƐŝƚǇŽĨƉƌĞƐǇŶĂƉƟĐ

dopaminergic terminals within the striatum.48_{Longitudinal studies that monitored}

ŶĞǁůǇ ĚŝĂŐŶŽƐĞĚ W ƉĂƟĞŶƚƐ ǁŝƚŚŽƵƚ ĞǀŝĚĞŶĐĞ ŽĨ ĚŽƉĂŵŝŶĞƌŐŝĐ ĚĞĮĐŝƚƐ ;ĂĐĐĞƐƐĞĚ ďǇ WdŽƌ^WdͿƐƵŐŐĞƐƚWdĂŶĚ^WdƚŽďĞǀĂůƵĂďůĞĚŝĂŐŶŽƐƟĐƚŽŽůƐĂƐƚŚĞŵĂũŽƌŝƚǇŽĨ

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ĚŽƉĂŵŝŶĞƌŐŝĐůŽƐƐ͘/ƚǁŽƵůĚďĞƉƌĞĨĞƌĂďůĞƚŽĂƉƉůǇĂĚŝĂŐŶŽƐƟĐƚŽŽůƚŚĂƚĐŽƵůĚŽďƐĞƌǀĞ WͲƌĞůĂƚĞĚƐǇŵƉƚŽŵĂƟĐŽƌƉĂƚŚŽůŽŐŝĐĐŚĂŶŐĞƐĞĂƌůŝĞƌŝŶƚŚĞĚŝƐĞĂƐĞƉƌŽĐĞƐƐƐƟůůůĞĂǀŝŶŐ the possibility to slow or alter the progressive disease. As the olfactory bulb is one of the ĮƌƐƚĂīĞĐƚĞĚďƌĂŝŶƌĞŐŝŽŶƐ͕ĂĐĐŽŵƉĂŶŝĞĚďǇĂůŽƐƐŽĨƐŵĞůů͕ƚŚĞhŶŝǀĞƌƐŝƚǇŽĨWĞŶŶƐǇůǀĂŶŝĂ

ƐŵĞůůŝĚĞŶƟĮĐĂƟŽŶƚĞƐƚŝƐƵƐĞĚƚŽŝŵƉƌŽǀĞĞĂƌůŝĞƌĚŝĂŐŶŽƐŝƐ͘50

Despite the absence of generally accepted pathological criteria,35_{the standard is}

ƚŽĐŽŶĮƌŵĐůŝŶŝĐĂůĚŝĂŐŶŽƐŝƐƉĂƚŚŽůŽŐŝĐĂůůǇŝŶƉŽƐƚͲŵŽƌƚĞŵďƌĂŝŶƟƐƐƵĞďǇƚŚĞƉƌĞƐĞŶĐĞ ŽĨƚŚĞƚǁŽĚŝƐĐƵƐƐĞĚƉĂƚŚŽůŽŐŝĐĂůŚĂůůŵĂƌŬƐ͗ŶĞƵƌŽĚĞŐĞŶĞƌĂƟŽŶŝŶƚŚĞ^EƉĐĂŶĚ>ĞǁǇ body pathology in surviving dopamine neurons, and the absence of pathological evidence

of other diseases producing similar clinical motor symptoms.51_{The acknowledgement}

ŽĨŶŽŶͲƚƌĂĚŝƟŽŶĂůĨĞĂƚƵƌĞƐŽĨWƚŚĂƚĂƌĞŶŽƚƐƚĂŶĚĂƌĚĂĐĐŽƵŶƚĞĚĨŽƌŝŶĚŝĂŐŶŽƐŝƐ͕ƐƵĐŚ ĂƐ ŐĞŶĞƟĐĂůůǇ ĐŽŶĮƌŵĞĚ W ƉĂƟĞŶƚƐ ǁŝƚŚŽƵƚ >ĞǁǇ ŽĚǇ ƉĂƚŚŽůŽŐǇ Žƌ ƚŚĞ ŝŵƉŽƌƚĂŶĐĞ ŽĨŶŽŶͲŵŽƚŽƌƐǇŵƉƚŽŵƐ͕ĞŵƉŚĂƐŝǌĞƐƚŚĞŶĞĐĞƐƐŝƚǇĨŽƌĐŽŶƟŶƵŽƵƐŝŵƉƌŽǀĞŵĞŶƚŽĨƚŚĞ ĚŝĂŐŶŽƐƟĐĐƌŝƚĞƌŝĂ͘52_{&ŽƌĨƵƚƵƌĞŝŵƉƌŽǀĞŵĞŶƚƐ͕ĞĂƌůǇĚŝĂŐŶŽƐŝƐďĞĨŽƌĞƚŚĞŽŶƐĞƚŽĨŵŽƚŽƌ} ƐǇŵƉƚŽŵƐŝŶƚŚĞƉƌŽĚƌŽŵĂůƉŚĂƐĞǁŽƵůĚďĞŵŽƐƚĞīĞĐƟǀĞĨŽƌĚƌƵŐƐĂŝŵŝŶŐƚŽƐůŽǁŽƌ ĂůƚĞƌƵŶĚĞƌůǇŝŶŐŶĞƵƌŽĚĞŐĞŶĞƌĂƟǀĞƉƌŽĐĞƐƐĞƐ͘

Although the development of such therapies has a high priority in ongoing PD research, the current drugs only treat the symptoms, thereby improving the quality of the ƉĂƟĞŶƚ͛ƐůŝĨĞ͘dƌĞĂƚŵĞŶƚƚŚĂƚĚŝŵŝŶŝƐŚŵŽƚŽƌƐǇŵƉƚŽŵƐŝŶĐƌĞĂƐĞďƌĂŝŶĚŽƉĂŵŝŶĞůĞǀĞůƐ Žƌ ƐƟŵƵůĂƚĞ ĚŽƉĂŵŝŶĞ ƌĞĐĞƉƚŽƌƐ͕ ŽĨ ǁŚŝĐŚ ƚŚĞ ŵŽƐƚ ĐŽŵŵŽŶůǇ ĂĚŵŝŶŝƐƚĞƌĞĚ ĚƌƵŐ ŝƐ levodopa.53_{ƐůĞǀŽĚŽƉĂŝƐĂĐĐŽŵƉĂŶŝĞĚďǇƐŝĚĞͲĞīĞĐƚƐĐĂƵƐŝŶŐŵŽƚŽƌĐŽŵƉůŝĐĂƟŽŶƐ͕ƐƵĐŚ} ĂƐĚǇƐŬŝŶĞƐŝĂĂŶĚŵŽƚŽƌŇƵĐƚƵĂƟŽŶƐ͕ƚŚĞĂĚŵŝŶŝƐƚƌĂƟŽŶŽĨůĞǀŽĚŽƉĂŝƐƉŽƐƚƉŽŶĞĚƵŶƟůƚŚĞ ƉĂƟĞŶƚĞǆƉĞƌŝĞŶĐĞƐĚŝƐĐŽŵĨŽƌƚ͘KƚŚĞƌŵŽƚŽƌƐǇŵƉƚŽŵŵĞĚŝĐĂƟŽŶƐĞŶĐŽŵƉĂƐƐĚŽƉĂŵŝŶĞ ĂŐŽŶŝƐƚƐ͕ŵŽŶŽĂŵŝŶĞŽǆŝĚĂƐĞƚǇƉĞŝŶŚŝďŝƚŽƌƐ͕ĂŶĚ͕ůĞƐƐĐŽŵŵŽŶůǇ͕ĂŵĂŶƚĂĚŝŶĞƚĂƌŐĞƟŶŐ

tremors, rigidity and bradykinesia.53,54_{Besides the therapies addressing motor symptoms,}

a limited number of treatments for non-motor symptoms are also available aiming to

ĚŝŵŝŶŝƐŚƐůĞĞƉŝŶŐƉƌŽďůĞŵƐ͕ƉƐǇĐŚŝĂƚƌŝĐƐǇŵƉƚŽŵƐĂŶĚĂƵƚŽŶŽŵŝĐŵĂůĨƵŶĐƟŽŶŝŶŐ͘53,55_As

ůĂƐƚ͕ƐƵƌŐŝĐĂůƚƌĞĂƚŵĞŶƚŝƐĂŶŽƚŚĞƌƚŚĞƌĂƉǇŽƉƟŽŶŝĨƚŚĞŵŽƚŽƌĐŽŵƉůŝĐĂƟŽŶƐŽĨůĞǀŽĚŽƉĂ become disabling in moderately to severely progressed PD (10 to 13 years post PD

diagnosis).56_{ĞĞƉďƌĂŝŶƐƟŵƵůĂƟŽŶŽĨƚŚĞƐƵďƚŚĂůĂŵŝĐŶƵĐůĞƵƐŽƌŐůŽďƵƐƉĂůůŝĚƵƐŝŶƚĞƌŶƵƐ}

ĐŽƵůĚďĞŶĞĮƚďŽƚŚŵŽƚŽƌƐǇŵƉƚŽŵƐĂŶĚŶŽŶͲŵŽƚŽƌƐǇŵƉƚŽŵƐ͘57

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ĚǇƐĨƵŶĐƟŽŶĂůďŝŽůŽŐŝĐĂůŵĞĐŚĂŶŝƐŵƐ͘dŚĞŝĚĞŶƟĮĐĂƟŽŶĂŶĚĐŚĂƌĂĐƚĞƌŝǌĂƟŽŶŽĨŐĞŶĞƟĐ

ĚĞĨĞĐƚƐ͕ ĂƐ ĐĂƵƐĂů ĨĂĐƚŽƌƐ ĨŽƌ W͕ ǁŝůů ĐŽŶƟŶƵĞ ƚŽ ŚĂǀĞ ĂŶ ŝŵƉŽƌƚĂŶƚ ŝŶŇƵĞŶĐĞ ŽŶ ƚŚĞ development of PD-related therapies.

'ĞŶĞƟĐĞƟŽůŽŐǇŽĨW

ŶŽƚŚĞƌ ŚĞƚĞƌŽŐĞŶĞŽƵƐ ĨĞĂƚƵƌĞ ŽĨ W ŝƐ ŝƚƐ ŐĞŶĞƟĐ ĞƟŽůŽŐǇ͘ dŚĞ ŚĞƌŝƚĂďŝůŝƚǇ ŽĨ W ŝƐ

ĞƐƟŵĂƚĞĚƚŽďĞĂƌŽƵŶĚϰϬй͘9,60,61_{The discovery of PD genes followed a similar trend as}

ŽďƐĞƌǀĞĚĨŽƌƚŚĞŐĞŶĞƌĂůƉƌŽŐƌĞƐƐŝŽŶŽĨŐĞŶĞƟĐĂŶĚŐĞŶŽŵŝĐƐƚĞĐŚŶŝƋƵĞƐ;ŽǆͿ͘&ŝƌƐƚ͕ ĨĂŵŝůǇͲďĂƐĞĚ ůŝŶŬĂŐĞ ĂŶĂůǇƐĞƐ ĂŶĚ ƉŽƉƵůĂƟŽŶͲďĂƐĞĚ ŐĞŶŽŵĞͲǁŝĚĞ ĂƐƐŽĐŝĂƟŽŶ ƐƚƵĚŝĞƐ ;'t^Ϳ ĚŽŵŝŶĂƚĞĚ ƚŚĞ ŐĞŶĞƟĐ ƌĞƐĞĂƌĐŚ ĮĞůĚ ĨŽƌ ĚĞĐĂĚĞƐ͕ ǁŚŝĐŚ ǁĂƐ ĨŽůůŽǁĞĚ ďǇ ƚŚĞ ĂƉƉůŝĐĂƟŽŶ ŽĨ ŶĞǆƚ ŐĞŶĞƌĂƟŽŶ ƐĞƋƵĞŶĐŝŶŐ ;E'^Ϳ ŵĞƚŚŽĚƐ ĚƵƌŝŶŐ ƚŚĞ ůĂƐƚ ĚĞĐĂĚĞ͘ dŚĞ ĮƌƐƚŐĞŶĞƚŽďĞůŝŶŬĞĚƚŽWǁĂƐSNCA, encoding for the main protein component of Lewy ďŽĚŝĞƐ͕ŽĨǁŚŝĐŚƌĂƌĞĂŶĚŚŝŐŚůǇƉĞŶĞƚƌĂŶƚŵƵƚĂƟŽŶƐǁĞƌĞƐŚŽǁŶƚŽĂŐŐƌĞŐĂƚĞǁŝƚŚƚŚĞ

ĚŝƐĞĂƐĞǁŝƚŚŝŶĨĂŵŝůŝĞƐƐŚŽǁŝŶŐĂƵƚŽƐŽŵĂůĚŽŵŝŶĂŶƚŝŶŚĞƌŝƚĂŶĐĞƉĂƩĞƌŶƐ͘62_Subsequent

ƌĞƐĞĂƌĐŚƐŚŽǁĞĚďŽƚŚŵŝƐƐĞŶƐĞŵƵƚĂƟŽŶƐĂŶĚĞǆŽŶŝĐŵƵůƟƉůŝĐĂƟŽŶƐƚŽďĞƚŚĞĐĂƵƐĂƟǀĞ

defects.63_{&ƵƌƚŚĞƌ ĨĂŵŝůǇͲďĂƐĞĚ ůŝŶŬĂŐĞ ƐƚƵĚŝĞƐ ƌĞƉŽƌƚĞĚ ƚŚĞ ŝŶǀŽůǀĞŵĞŶƚ ŽĨ ĂĚĚŝƟŽŶĂů}

genes in the development of monogenic forms of parkinsonism. Another autosomal

dominant inherited parkinsonism gene is LRRK2,64_{ŽĨ ǁŚŝĐŚ ƚŚĞ ƉĂƚŚŽŐĞŶŝĐ ŵƵƚĂƟŽŶƐ}

ĂƌĞƉƌĞĚŽŵŝŶĂŶƚůǇůŽĐĂƚĞĚǁŝƚŚŝŶƚŚĞĐĂƚĂůǇƟĐĚŽŵĂŝŶƐŽĨƚŚĞĞŶĐŽĚĞĚƉƌŽƚĞŝŶ͘65_LRRK2

ŵƵƚĂƟŽŶƐĂƌĞĨƵƌƚŚĞƌŵŽƌĞƚŚĞŵŽƐƚĐŽŵŵŽŶŐĞŶĞƟĐĐĂƵƐĞĨŽƌŝĚŝŽƉĂƚŚŝĐW͘66_Parkin,67

PINK168_{and DJ-1}69_{are genes associated to parkinsonism with an autosomal recessive}

ŝŶŚĞƌŝƚĂŶĐĞ ƉĂƩĞƌŶ͕ ǁŚŝĐŚ ŝƐ ŵŽƐƚůǇ ƐĞĞŶ ŝŶ ƚŚĞ zKW ƐƵďƚǇƉĞ͘10_{Besides the familial}

PD cases, sporadic PD cases with an early onset of PD have also been observed with

ƉĂƚŚŽŐĞŶŝĐŵƵƚĂƟŽŶƐŝŶPINK173,74_{and parkin}75-77_{, ŵĂŬŝŶŐƚŚĞůĂƩĞƌŐĞŶĞƚŚĞŵŽƐƚ}

ĐŽŵŵŽŶŐĞŶĞƟĐĨĂĐƚŽƌ;ϭϬͲϮϬйͿĨŽƌzKW͘78_{dŚĞƐĞϱWŐĞŶĞƐǁĞƌĞĚĞĮŶĞĚĂƐƚŚĞŐĞŶĞƟĐ}

ĚŝƐĐŽǀĞƌŝĞƐǁŝƚŚĐŽŶĐůƵƐŝǀĞĞǀŝĚĞŶĐĞƌĞƐƵůƟŶŐĨƌŽŵƚŚĞůŝŶŬĂŐĞĂŶĂůǇƐŝƐĞƌĂ͘

dŚƌĞĞĂĚĚŝƟŽŶĂůŐĞŶĞƐůŝŶŬĞĚƚŽŵŽŶŽŐĞŶŝĐĨŽƌŵƐŽĨƉĂƌŬŝŶƐŽŶŝƐŵŚĂǀĞďĞĞŶ ĚŝƐĐŽǀĞƌĞĚǁŝƚŚE'^͕ŽĨǁŚŝĐŚVPS35 ǁĂƐƚŚĞĮƌƐƚŽŶĞƚŽďĞŝĚĞŶƟĮĞĚ͘dǁŽŝŶĚĞƉĞŶĚĞŶƚ studies reported VPS35ŵƵƚĂƟŽŶƐŝŶƵƐƚƌŝĂŶĂŶĚ^ǁŝƐƐĨĂŵŝůŝĞƐĚŝĂŐŶŽƐĞĚǁŝƚŚĂƵƚŽƐŽŵĂů

dominant PD.79,80_{More recently, DNAJC13}81_{and CHCHD2}82_{have also been linked to}

ĚŽŵŝŶĂŶƚůǇ ŝŶŚĞƌŝƚĞĚ ƉĂƌŬŝŶƐŽŶŝƐŵ ďǇ ŝŵƉůĞŵĞŶƟŶŐ ǁŚŽůĞ ĞǆŽŵĞ ƐĞƋƵĞŶĐŝŶŐ ;t^Ϳ͘

ůƚŚŽƵŐŚWĐĂƐĞͲƐƉĞĐŝĮĐCHCHD2 variants have also been observed in a second study,83

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Box A. Genome-wide research techniques

The ůŝŶŬĂŐĞŵĞƚŚŽĚǁĂƐĚĞǀĞůŽƉĞĚĚƵƌŝŶŐƚŚĞĞŝŐŚƟĞƐŽĨƚŚĞůĂƐƚĐĞŶƚƵƌǇĂŶĚǁĂƐƚŚĞĮƌƐƚ ƚĞĐŚŶŝƋƵĞƚŽĞǆƉůŽƌĞƚŚĞĨƵůůŐĞŶŽŵĞŝŶĂŶƵŶďŝĂƐĞĚĨĂƐŚŝŽŶůĂĐŬŝŶŐĂƐƐƵŵƉƟŽŶƐĂďŽƵƚŐĞŶĞ ĨƵŶĐƟŽŶƐ ƉƵƚĂƟǀĞůǇ ŝŶǀŽůǀĞĚ ŝŶ ďŝŽůŽŐŝĐĂů ƉĂƚŚǁĂǇƐ ƌĞůĂƚĞĚ ƚŽ ƚŚĞ ĚŝƐĞĂƐĞ ƉĂƚŚŽŐĞŶĞƐŝƐ ŽĨ interest.70_{ZĞůĂƟǀĞƐƐŚĂƌĞůĂƌŐĞƉŝĞĐĞƐŽĨE͕ƚŚĞƌĞĨŽƌĞĞŶĂďůŝŶŐƚŚĞĐŽŵƉĂƌŝƐŽŶŽĨŝĚĞŶƟĐĂů} ŐĞŶŽŵŝĐƌĞŐŝŽŶƐďĞƚǁĞĞŶĨĂŵŝůǇŵĞŵďĞƌƐǁŝƚŚĂƌĞůĂƟǀĞƐŵĂůůŶƵŵďĞƌŽĨŐĞŶĞƟĐŵĂƌŬĞƌƐ͘ ǇƐĞůĞĐƟŶŐƚŚŽƐĞŐĞŶŽŵŝĐƌĞŐŝŽŶƐƚŚĂƚŽǀĞƌůĂƉŝŶƉĂƟĞŶƚƐďƵƚŶŽƚŝŶŚĞĂůƚŚǇƌĞůĂƟǀĞƐŝƚŝƐ possible to decrease the genomic region that might contain the rare and highly-penetrant causal variant. dŚĞĐŽŵƉůĞƟŽŶŽĨƚŚĞĨƵůůŚƵŵĂŶEƐĞƋƵĞŶĐĞŝŶϮϬϬϭǁĂƐĨŽůůŽǁĞĚďǇƚŚĞŝĚĞŶƟĮĐĂƟŽŶŽĨ ŵŝůůŝŽŶƐŽĨƐŝŶŐůĞŶƵĐůĞŽƟĚĞƉŽůǇŵŽƌƉŚŝƐŵƐ;ÊWƐͿ͕ǁŚŝĐŚĂƌĞŝŶŐĞŶĞƌĂůĚĞĮŶĞĚĂƐǀĂƌŝĂŶƚƐ ƚŚĂƚĂƌĞĐŽŵŵŽŶŝŶƚŚĞŐĞŶĞƌĂůƉŽƉƵůĂƟŽŶ͘dŚĞƐĞÊWƐƐĞƌǀĞĚĂƐƚŚĞĨŽƵŶĚĂƟŽŶƵƉŽŶǁŚŝĐŚ ŐĞŶŽŵĞͲǁŝĚĞ ĂƐƐŽĐŝĂƟŽŶ ƐƚƵĚŝĞƐ ;'t^Ϳ ǁŽƵůĚ ďƵŝůĚ ŽŶ͕ ƌĞƐƵůƟŶŐ ŝŶ ƚŚĞ ĮƌƐƚ ƉƵďůŝƐŚĞĚ 't^ŽŶĂƐƉĞĐŝĮĐƚǇƉĞŽĨďůŝŶĚŶĞƐƐŝŶϮϬϬϱ͘71_{ÊWƐƚŚĂƚĂƌĞƌĞůĂƟǀĞůǇĐůŽƐĞůǇůŽĐĂƚĞĚƚŽŽŶĞ}

another are likely to be simultaneously inherited as a block, and are called to be in linkage

disequilibrium (LD).72_{/ŶƉƌŝŶĐŝƉůĞ͕ŽŶĞ^EWĨŽƌĞĂĐŚ>ďůŽĐŬŽĨƚŚĞŐĞŶŽŵĞǁŽƵůĚďĞƐƵĸĐŝĞŶƚ}

ƚŽƚĞƐƚĨŽƌƚŚĞĞīĞĐƚŽĨŐĞŶĞƟĐǀĂƌŝĂƟŽŶƚŽĂƚƌĂŝƚ͘dŚĞƌĞĨŽƌĞ͕'t^ƵƐĞƐĂƐĞůĞĐƟŽŶŽĨ^EWƐ ƚŚĂƚĐĂƉƚƵƌĞŵŽƐƚŽĨƚŚĞĂůůĞůŝĐǀĂƌŝĂƟŽŶŝŶƚŚĞƐƵƌƌŽƵŶĚŝŶŐƌĞŐŝŽŶ͘'t^ŚĂƐĂĚŝƐƟŶĐƚƐƚƵĚǇ ĚĞƐŝŐŶĨƌŽŵůŝŶŬĂŐĞ͕ĂƐƚŚĞƐƚƵĚǇƐƵďũĞĐƚƐĞŶĐŽŵƉĂƐƐƵŶƌĞůĂƚĞĚŝŶĚŝǀŝĚƵĂůƐ͕ƚǇƉŝĐĂůůǇĐŽŶƐŝƐƟŶŐ ŽĨĂĐĂƐĞĂŶĚĐŽŶƚƌŽůŐƌŽƵƉĨŽƌĚŝƐĞĂƐĞͲƌĞůĂƚĞĚŐĞŶĞƟĐƌĞƐĞĂƌĐŚ͘

During the last decade, ŶĞǆƚͲŐĞŶĞƌĂƟŽŶƐĞƋƵĞŶĐŝŶŐ;E'^ͿŚĂƐƌĞǀŽůƵƟŽŶŝǌĞĚƚŚĞŐĞŶŽŵŝĐƐ ĮĞůĚ͘ dŚŝƐ ƚĞĐŚŶŝƋƵĞ ƵƐĞƐ ŵĂƐƐŝǀĞůǇ ƉĂƌĂůůĞů ƐĞƋƵĞŶĐŝŶŐ͕ ŵĞĂŶŝŶŐ ƚŚĂƚ ŵŝůůŝŽŶƐ ŽĨ EͲ molecules are simultaneously processed allowing a single genome to be sequenced in a ƟŵĞͲĨƌĂŵĞŽĨĂƉƉƌŽǆŝŵĂƚĞůǇŽŶĞĚĂǇ͘ůůŶƵĐůĞŽƟĚĞƐŽĨƚŚĞƐĞƋƵĞŶĐĞĂƌĞĐŽǀĞƌĞĚƚŚĞƌĞĨŽƌĞ ĞŶĂďůŝŶŐƚŽĂŶĂůǇǌĞĞǀĞƌǇƐŝŶŐůĞďĂƐĞ͕ŝŶĐƌĞĂƐŝŶŐƚŚĞůŝŬĞůŝŚŽŽĚƚŽĮŶĚƚŚĞƚƌƵĞĐĂƵƐĂůǀĂƌŝĂŶƚ͘ ůƚŚŽƵŐŚ ƚŚĞ ĐŽƐƚƐ ĨŽƌ ŐĞŶŽŵĞ ƐĞƋƵĞŶĐŝŶŐ ŚĂǀĞ ĚĞĐƌĞĂƐĞĚ ƐƵďƐƚĂŶƟĂůůǇ͕ ŝƚ ŝƐ ƐƟůů ƌĞůĂƟǀĞůǇ ĞǆƉĞŶƐŝǀĞ͘ŶĂůƚĞƌŶĂƟǀĞĂŶĚĐŚĞĂƉĞƌE'^ƚĞĐŚŶŝƋƵĞŝƐƚĂƌŐĞƚĞĚƐĞƋƵĞŶĐŝŶŐǁŚĞƌĞƐƉĞĐŝĮĐ ŐĞŶŽŵŝĐƌĞŐŝŽŶƐ͕ƚŚĂƚĂƌĞĞǆƉĞĐƚĞĚƚŽĐŽŶƚĂŝŶĚŝƐĞĂƐĞͲĂƐƐŽĐŝĂƚĞĚǀĂƌŝĂŶƚƐ͕ĂƌĞƐĞƋƵĞŶĐĞĚ͘KŶĞ ĞǆĂŵƉůĞŽĨƚĂƌŐĞƚĞĚƐĞƋƵĞŶĐŝŶŐŝƐǁŚŽůĞͲĞǆŽŵĞƐĞƋƵĞŶĐŝŶŐ͘ ĞƐŝĚĞƐƚŚĞƌĂƌĞǀĂƌŝĂŶƚƐǁŝƚŚŚŝŐŚĞīĞĐƚƐŝǌĞƐĞǆƉůĂŝŶŝŶŐƚŚĞŐĞŶĞƟĐǀĂƌŝĂďŝůŝƚǇ ŝŶDĞŶĚĞůŝĂŶƚǇƉĞƐŽĨW͕ŵĂŶǇ't^84-88_{ŝĚĞŶƟĮĞĚĐŽŵŵŽŶƌŝƐŬǀĂƌŝĂŶƚƐĐŽŶƚƌŝďƵƟŶŐ} ƚŽŵƵůƟĨĂĐƚŽƌŝĂůW͕ǁŚŝĐŚǁĂƐĞǆƉĞĐƚĞĚƚŽĞǆƉůĂŝŶĂŶĂĚĚŝƟŽŶĂůƉĂƌƚŽĨƚŚĞŚĞƌŝƚĂďŝůŝƚǇ ĞƐƟŵĂƚĞƐ͘89_{dŚĞŵŽƐƚƌĞĐĞŶƚĂŶĚůĂƌŐĞƐƚŵĞƚĂͲĂŶĂůǇƐŝƐŽĨ't^ĚĂƚĂ͕ŝŶĐůƵĚŝŶŐϭϯ͕ϳϬϴW} ĐĂƐĞƐĂŶĚϵϱ͕ϮϴϮŚĞĂůƚŚǇĐŽŶƚƌŽůƐŽĨƵƌŽƉĞĂŶĂŶĐĞƐƚƌǇ͕ŝĚĞŶƟĮĞĚϮϰůŽĐŝƚŚĂƚĐŽŶƚƌŝďƵƚĞ ƚŽ W ƐƵƐĐĞƉƟďŝůŝƚǇ ĐŽŶĮƌŵŝŶŐ ŵĂŶǇ ƉƌĞǀŝŽƵƐůǇ ŝĚĞŶƟĮĞĚ W ŐĞŶĞƐ͘90_{Among these}

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ĐŽŶĮƌŵĞĚĂƐĂŐĞŶŽŵĞͲǁŝĚĞƐŝŐŶŝĮĐĂŶƚŐĞŶĞƟĐƌŝƐŬĨĂĐƚŽƌ͘/ŶŝƟĂůůǇGBA was suggested to

ĐŽŶƚƌŝďƵƚĞƚŽWƌŝƐŬďĂƐĞĚŽŶĐůŝŶŝĐĂůŽďƐĞƌǀĂƟŽŶƐǁŚĞƌĞƐŽŵĞ'ĂƵĐŚĞƌĚŝƐĞĂƐĞƉĂƟĞŶƚƐ͕ ŽŌĞŶĐĂƵƐĞĚďǇGBA ŵƵƚĂƟŽŶƐǁŝƚŚĂƵƚŽƐŽŵĂůƌĞĐĞƐƐŝǀĞŝŶŚĞƌŝƚĂŶĐĞƉĂƩĞƌŶ͕ƉƌĞƐĞŶƚĞĚ

symptoms resembling Parkinsonism.91,92_{Subsequent large-scale research aiming to}

convincingly verify the importance of GBA for PD, reported a 5-fold increase to develop

WĨŽƌŚĞƚĞƌŽǌǇŐŽƵƐGBA carriers.93_{ůƚŚŽƵŐŚƚŚĞϮϰŝŶĚĞƉĞŶĚĞŶƚĐŽŵŵŽŶŐĞŶĞƟĐƌŝƐŬ} ĨĂĐƚŽƌƐ ǁŝƚŚ ŵŽĚĞƌĂƚĞ ĞīĞĐƚ ƐŝǌĞƐ ĂƌĞ ŶŽƚ ŽĨ ŐƌĞĂƚ ǀĂůƵĞ ĨŽƌ ŝŶĚŝǀŝĚƵĂů ĚŝĂŐŶŽƐŝƐ͕ ƚŚĞǇ ĂƌĞŝŵƉŽƌƚĂŶƚĨŽƌŚŝŐŚůŝŐŚƟŶŐŝŵƉĂŝƌĞĚďŝŽůŽŐŝĐĂůƉƌŽĐĞƐƐĞƐŝŶWƉĂƚŚŽŐĞŶĞƐŝƐ͘&ƵƚƵƌĞ ƐƚƵĚŝĞƐƐŚŽƵůĚĚĞĐŝƉŚĞƌǁŚŝĐŚŐĞŶĞƐƵŶĚĞƌŶĞĂƚŚƚŚĞ't^ƉĞĂŬƐĂƌĞƚŚĞĂĐƚƵĂůĐĂƵƐĂů ŽŶĞƐĂŶĚƚŚƌŽƵŐŚǁŚŝĐŚŵŽůĞĐƵůĂƌƉĂƚŚǁĂǇƐƚŚĞǇŝŶŇƵĞŶĐĞƚŚĞĚĞǀĞůŽƉŵĞŶƚŽĨW͘ ŽƚŚƚŚĞĚŝƐĐŽǀĞƌǇŽĨƚŚĞDĞŶĚĞůŝĂŶŐĞŶĞƐĂŶĚƚŚĞŐĞŶĞƟĐƌŝƐŬůŽĐŝĞǆƉĂŶĚĞĚƚŚĞ ŬŶŽǁůĞĚŐĞĂďŽƵƚƵŶĚĞƌůǇŝŶŐďŝŽůŽŐŝĐĂůŵĞĐŚĂŶŝƐŵƐƚŚĂƚĞǆƉĞƌŝĞŶĐĞĚĞĨĞĐƚƐĐŽŶƚƌŝďƵƟŶŐ ƚŽWƐƵƐĐĞƉƟďŝůŝƚǇ͘&ŝƌƐƚ͕ƚŚĞŐĞŶĞƐƌĞůĂƚĞĚƚŽŵŽŶŽŐĞŶŝĐĨŽƌŵƐŽĨWŚĂǀĞƉƵƚĞŵƉŚĂƐŝǌĞ ŽŶƚŚƌĞĞďŝŽůŽŐŝĐĂůŵĞĐŚĂŶŝƐŵƐ͗ƐǇŶĂƉƟĐĨƵŶĐƟŽŶ͕ůǇƐŽƐŽŵĞͲŵĞĚŝĂƚĞĚĂƵƚŽƉŚĂŐǇĂŶĚ mitochondrial maintenance.59_{dŚĞŚǇƉŽƚŚĞƐŝƐƚŚĂƚƐǇŶĂƉƟĐƚƌĂŶƐŵŝƐƐŝŽŶŝŵƉĂŝƌŵĞŶƚƐĂƌĞ}

ŝŵƉŽƌƚĂŶƚŝŶWĞŵĞƌŐĞĚĨƌŽŵƚŚĞĚŝƐĐŽǀĞƌǇŽĨŵƵƚĂƟŽŶƐŝŶSNCA, the main component

ŽĨ>͕ĂŶĚŝƐĂƉƌĞƐǇŶĂƉƟĐƉƌŽƚĞŝŶƉƌŽŵŽƟŶŐĞǆŽĐǇƚŽƐŝƐ͘94_{dŚĞŝĚĞŶƟĮĐĂƟŽŶŽĨLRRK2,}

Ă ƉƌŽƚĞŝŶ ŝŶ ƚŚĞ ƉŽƐƚƐǇŶĂƉƟĐ ƚĞƌŵŝŶĂů ƐƵŐŐĞƐƚĞĚ ƚŽ ŚĂǀĞ Ă ĨƵŶĐƟŽŶ ŝŶ ĞŶĚŽĐǇƚŽƐŝƐ͕95

ƐƚƌĞŶŐƚŚĞŶƐ ƚŚŝƐ ƚŚĞŽƌǇ͘ &ƵƌƚŚĞƌŵŽƌĞ͕ ƚŚĞ zKWͲĂƐƐŽĐŝĂƚĞĚ ŐĞŶĞ parkin inhibits the

ĂĐƟǀŝƚǇ ŽĨ ĞǆĐŝƚĂƚŽƌǇ ƐǇŶĂƉƐĞƐ͘96_{WƌĞͲ ĂŶĚ ƉŽƐƚƐǇŶĂƉƟĐ ƉƌŽĐĞƐƐĞƐ ŵŝŐŚƚ ƚŚĞƌĞĨŽƌĞ ďĞ}

suitable targets for future treatment strategies. SNCA and LRRK2 ŚĂǀĞĂĚĚŝƟŽŶĂůƌŽůĞƐŝŶ ĂƵƚŽƉŚĂŐǇƉƌŽĐĞƐƐĞƐ;ŝŶƚƌĂĐĞůůƵůĂƌĚĞŐƌĂĚĂƟŽŶƐǇƐƚĞŵͿ͕ĞƐƉĞĐŝĂůůǇŝŶĐŚĂƉĞƌŽŶͲŵĞĚŝĂƚĞĚ

autophagy.97-99_{dŚŝƐ ƐƉĞĐŝĮĐ ĨŽƌŵ ŽĨ ĂƵƚŽƉŚĂŐǇ͕ ƐĞůĞĐƟŶŐ ƉĂƌƟĐƵůĂƌ ĐĂƌŐŽ͕ ŝƐ Ă ƚǇƉĞ ŽĨ}

ůǇƐŽƐŽŵĂů ĚĞŐƌĂĚĂƟŽŶ͘100_{VPS35 ĂůƐŽ ŚĂƐ Ă ƌŽůĞ ŝŶ ůǇƐŽƐŽŵĂů ĚĞŐƌĂĚĂƟŽŶ ƚŚƌŽƵŐŚ ŝƚƐ}

ĨƵŶĐƟŽŶŝŶŵĞĚŝĂƟŶŐƌĞƚƌŽŐƌĂĚĞƚƌĂŶƐƉŽƌƚŽĨĐĂƌŐŽĂŶĚŝƐĂĐŽŵƉŽŶĞŶƚŽĨƚŚĞƌĞƚƌŽŵĞƌĂŶĚ ŝƚƐĚĞĨĞĐƚƐĐŽƵůĚůĞĂĚƚŽƚƌĂĸĐŬŝŶŐŝƐƐƵĞƐŽĨĂůǇƐŽƐŽŵĞƉƌŽƚĞĂƐĞŝŶǀŽůǀĞĚŝŶɲͲƐǇŶƵĐůĞŝŶ

ĚĞŐƌĂĚĂƟŽŶ͘101_{GBA ĞŶĐŽĚĞƐĨŽƌĂůǇƐŽƐŽŵĂůĂĐŝĚŚǇĚƌŽůĂƐĞƐĂŶĚŵƵƚĂƟŽŶƐŝŶGBA are}

ƐƵŐŐĞƐƚĞĚƚŽƌĞƐƵůƚŝŶŽǀĞƌĂůůůǇƐŽƐŽŵĂůĚǇƐĨƵŶĐƟŽŶĂŶĚĂƵƚŽƉŚĂŐǇŝŵƉĂŝƌŵĞŶƚƐ͘102,103_In

ĂĚĚŝƟŽŶ͕ŚŽŵŽǌǇŐŽƵƐŵƵƚĂƟŽŶƐǁŝƚŚŝŶGBAĐĂƵƐĞ'ĂƵĐŚĞƌĚŝƐĞĂƐĞ͕ǁŚŝĐŚŝƐĂůǇƐŽƐŽŵĂů

storage disorder.104_{These studies imply that LRRK2, SNCA, VPS35 and GBA all have a}

ĨƵŶĐƟŽŶŝŶƚŚĞůǇƐŽƐŽŵĂůͲŵĞĚŝĂƚĞĚĂƵƚŽƉŚĂŐǇƉƌŽĐĞƐƐ͕ƉƌŽǀŝĚŝŶŐ ĂƉƵƚĂƟǀĞƚĂƌŐĞƚĨŽƌ ƌĞƐĞĂƌĐŚƵůƟŵĂƚĞůǇƌĞƐƵůƟŶŐŝŶŝŵƉƌŽǀĞĚƚŚĞƌĂƉĞƵƟĐŝŶƚĞƌǀĞŶƟŽŶƐ͘

dŚĞ ƉƌŽĐĞƐƐĞƐ ƚŽ ŵĂŝŶƚĂŝŶ ŵŝƚŽĐŚŽŶĚƌŝĂů ŚĞĂůƚŚ ĂƌĞ ĂĚĚŝƟŽŶĂů ŵŽůĞĐƵůĂƌ ŵĞĐŚĂŶŝƐŵƐƚŚĂƚĂƌĞŝŵƉůŝĞĚƚŽŝŶŇƵĞŶĐĞWĚĞǀĞůŽƉŵĞŶƚďǇƚŚĞĚŝƐĐŽǀĞƌǇŽĨƚŚĞzKW genes parkin, PINK1 and DJ-1. Parkin and PINK1 are suggested to be closely related

as they both have roles in mitophagy,105_{ǁŚŝĐŚ ĞŶĐŽŵƉĂƐƐĞƐ ĂƵƚŽƉŚĂŐǇ ŽĨ ĚĞĮĐŝĞŶƚ}

mitochondria. Parkin ŝƐŝŶŐĞŶĞƌĂůƉƌĞƐĞŶƚŝŶƚŚĞĐǇƚŽƐŽůďƵƚůŽĐĂůŝǌĞƐƚŽƚŚĞŵŝƚŽĐŚŽŶĚƌŝĂ ǁŚĞŶ ƚŚĞǇ ĚĞƉŽůĂƌŝǌĞ ƚŽ ƐĞƌǀĞ ĂƐ Ă ŵĞĚŝĂƚŽƌ ĨŽƌ ĂƵƚŽƉŚĂŐǇ ŽĨ ƚŚĞ ƐƉĞĐŝĮĐ ĚĂŵĂŐĞĚ

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ĚǇƐĨƵŶĐƟŽŶĂů ŵŝƚŽĐŚŽŶĚƌŝĂ͕ ĂĐĐƵŵƵůĂƚĞƐ ŽŶ ƚŚĞŵ ĂŶĚ ƐƵďƐĞƋƵĞŶƚůǇ ƐŝŐŶĂůƐ parkin.107

Parkin ubiquinates mitochondrial substrates on the outer membrane, thereby informing ƚŚĞůǇƐŽƐŽŵĞǁŚŝĐŚŵŝƚŽĐŚŽŶĚƌŝŽŶƐŚŽƵůĚďĞĚĞŐƌĂĚĞĚ͘dŚĞƚŚŝƌĚzKWŐĞŶĞDJ-1 is not ĂĐƟǀĞŝŶŵŝƚŽƉŚĂŐǇ͕ďƵƚƐĞĞŵƐƚŽǁŽƌŬŝŶƉĂƌĂůůĞůƚŽƉƌŽƚĞĐƚŵŝƚŽĐŚŽŶĚƌŝĂĂŐĂŝŶƐƚŽǆŝĚĂƟǀĞ

stress.108_{The recently discovered PD gene CHCHD2ŝƐƐƵŐŐĞƐƚĞĚƚŽŚĂǀĞĂĨƵŶĐƟŽŶĂůƌŽůĞ}

ŝŶŵŝƚŽĐŚŽŶĚƌŝĂůƌĞƐƉŝƌĂƟŽŶ͘82_{Therefore, a total of 4 genes point to the importance of}

ŚĞĂůƚŚǇŵŝƚŽĐŚŽŶĚƌŝĂůƉƌŽĐĞƐƐĞƐĨŽƌĂĚĞƋƵĂƚĞĨƵŶĐƟŽŶŝŶŐŽĨĚŽƉĂŵŝŶĞƌŐŝĐŶĞƵƌŽŶƐ͘ dŚĞ ŝĚĞŶƟĮĐĂƟŽŶ ŽĨ ƚŚĞ ĐŽŵŵŽŶ ŐĞŶĞƟĐ ƌŝƐŬ ĨĂĐƚŽƌƐ ďǇ 't^ ŚĂƐ ƌĞǀĞĂůĞĚ ĂŶĂĚĚŝƟŽŶĂůďŝŽůŽŐŝĐĂůƉĂƚŚǁĂǇƚŽďĞŝŶǀŽůǀĞĚŝŶWƉĂƚŚŽŐĞŶĞƐŝƐ͘ŝīĞƌĞŶƚůŽĐŝ;ŶĞĂƌ HLA-DRA, HLA-DRB1, HLA-DRB5 and HLA-DQB1) of the HLA region on chromosome 6

are associated to PD.87,90,109,110_{This region harbors many genes encoding molecules that}

ĂƌĞŝŵƉŽƌƚĂŶƚĨŽƌĂĚĂƉƟǀĞŝŵŵƵŶĞƌĞƐƉŽŶƐĞ͘dŚĞĚŝƐĐŽǀĞƌǇŽĨƚŚĞƐĞůŽĐŝƐƚƌĞŶŐƚŚĞŶĞĚ ƚŚĞŝŶǀŽůǀĞŵĞŶƚŽĨƚŚĞŝŵŵƵŶĞƐǇƐƚĞŵŝŶWĞƟŽůŽŐǇ͕ǁŚŝĐŚǁĂƐƉƌĞǀŝŽƵƐůǇŝŵƉůŝĞĚďǇ ŽďƐĞƌǀĂƟŽŶƐŽĨŶĞƵƌŽŝŶŇĂŵŵĂƟŽŶĂŶĚŝŶŶĂƚĞŝŵŵƵŶŝƚǇŝŶƚŚĞĐĞƌĞďƌŽƐƉŝŶĂůŇƵŝĚĂŶĚ ƉŽƐƚͲŵŽƌƚĞŵ ďƌĂŝŶ ƟƐƐƵĞƐ ŽĨ W ƉĂƟĞŶƚƐ͘111_{dŚĞƐĞ ŐĞŶĞƟĐ ĮŶĚŝŶŐƐ ĨƵƌƚŚĞƌŵŽƌĞ ŝŵƉůǇ} ƚŚĂƚƚŚĞŽďƐĞƌǀĞĚŶĞƵƌŽŝŶŇĂŵŵĂƟŽŶŝƐĂĐĂƵƐĞƌĂƚŚĞƌƚŚĂŶĂƌĞƐƵůƚŽĨŶĞƵƌŽŶĂůůŽƐƐ͘ ůƚŚŽƵŐŚ ƚŚĞ ŝĚĞŶƟĮĞĚ ŐĞŶĞƟĐ ĨĂĐƚŽƌƐ ĂƌĞ ŶŽƚ ĂƉƉůŝĐĂďůĞ ĨŽƌ ŝŶĚŝǀŝĚƵĂů ĚŝĂŐŶŽƐŝƐŽƌĂƐĚŝƌĞĐƚƚĂƌŐĞƚƐĨŽƌƚŚĞƌĂƉĞƵƟĐŝŶƚĞƌǀĞŶƟŽŶƐ͕ƚŚĞǇŚĂǀĞůĞĚƚŽĂŶŝŵƉƌŽǀĞĚ ƵŶĚĞƌƐƚĂŶĚŝŶŐ ŽĨ ƚŚĞ ƵŶĚĞƌůǇŝŶŐ ĐĞůůƵůĂƌ ƉƌŽĐĞƐƐĞƐ ĐŽŶƚƌŝďƵƟŶŐ ƚŽ W ƉĂƚŚŽŐĞŶĞƐŝƐ͘ ǆƚĞŶƐŝǀĞĐŽŵƉƌĞŚĞŶƐŝŽŶŽĨƚŚĞƐĞĂīĞĐƚĞĚďŝŽůŽŐŝĐĂůŵĞĐŚĂŶŝƐŵƐŝƐƌĞƋƵŝƌĞĚƚŽĚĞǀĞůŽƉ treatments that are not only aiming to relieve the symptoms, but would be able to alter ƚŚĞĚŝƐĞĂƐĞƉƌŽŐƌĞƐƐŝŽŶŽƌƵůƟŵĂƚĞůǇĐƵƌĞƚŚĞĚŝƐĞĂƐĞ͘dŚĞŝĚĞŶƟĮĐĂƟŽŶŽĨDĞŶĚĞůŝĂŶ ŐĞŶĞƐǁŝƚŚƐƚƌŽŶŐĞīĞĐƚƐĂŶĚƌŝƐŬůŽĐŝǁŝƚŚŵŽĚĞƌĂƚĞĞīĞĐƚƐĞǆƉůĂŝŶŽŶůǇƵƉƚŽϱϬйŽĨƚŚĞ

ŐĞŶĞƟĐǀĂƌŝĂƟŽŶ͕9,60_{ŝŵƉůǇŝŶŐƚŚĞĞǆŝƐƚĞŶĐĞŽĨƵŶĐŽǀĞƌĞĚŐĞŶĞƟĐĨĂĐƚŽƌƐĐŽŶƚƌŝďƵƟŶŐƚŽ}

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WŽƉƵůĂƚŝŽŶǀĂƌŝĂŶƚĨƌĞƋƵĞŶĐǇ ,ŝŐŚ ŝŵƉĂĐƚ ,ŝŐŚ ŝŵƉĂĐƚ ǆƚƌĞŵĞůǇƌĂƌĞ ŽŵŵŽŶ >Žǁ ŝŵƉĂĐƚ s ĂƌŝĂŶ ƚĞ ĨĨ Ğ Đƚ Ɛŝǌ Ğ PINK1 SNCA LRRK2 parkin DNAJC13 CHCHD2 DJ-1 VPS35 GBA BST1 SIPA1L2 SNCA INPP5F ASH1L TMEM175

MAPT RIT2 TMEM229B

CCDC62 UBOX5 TMPRSS9 BCKDK FAM47E MCCC1 GCH1 NUCKS1 DLG2 LRRK2 GPNMB HLA-DQB1 STK39 Figure 1.WͲĂƐƐŽĐŝĂƚĞĚŐĞŶĞƐĂŶĚƌŝƐŬůŽĐŝŝŶƉĞƌƐƉĞĐƟǀĞŽĨǀĂƌŝĂŶƚƚǇƉĞ͘ tŚŽůĞĞǆŽŵĞƐĞƋƵĞŶĐŝŶŐ

Subsequent to the popular family-based linkage analyses in the last two decades of the 20th

ĐĞŶƚƵƌǇƚŚĂƚƌĞǀĞĂůĞĚŵĂŶǇŶŽǀĞůŐĞŶĞƐĐĂƵƐŝŶŐDĞŶĚĞůŝĂŶƚǇƉĞƐŽĨĚŝƐĞĂƐĞƐ͕ƚŚĞŐĞŶĞƟĐ ƌĞƐĞĂƌĐŚĐŽŵŵƵŶŝƚǇĞƐƚĂďůŝƐŚĞĚŵĞƚŚŽĚƐƚŽŐĞŶĞƟĐĂůůǇƐƚƵĚǇƉŽƉƵůĂƟŽŶƐĞŶĐŽŵƉĂƐƐŝŶŐ unrelated samples,112_{ĂƐ ĚĞƐĐƌŝďĞĚ ŝŶ ďŽǆ ͘ Ǉ ĞǆƉůŽƌŝŶŐ ƚŚĞ ŐĞŶĞƟĐ ŝŶǀŽůǀĞŵĞŶƚ ŽĨ} ĐŽŵŵŽŶƌŝƐŬǀĂƌŝĂŶƚƐŝŶĐŽŵƉůĞǆŵƵůƟĨĂĐƚŽƌŝĂůĚŝƐŽƌĚĞƌƐ͕ŝŶƐƚĞĂĚŽĨƚŚĞƌĂƌĞǀĂƌŝĂŶƚƐǁŝƚŚ ƐƚƌŽŶŐĞīĞĐƚƐŝĚĞŶƟĮĞĚďǇƚŚĞĨĂŵŝůǇďĂƐĞĚƐƚƵĚŝĞƐ͕ŝƚǁĂƐĂŶƟĐŝƉĂƚĞĚƚŚĂƚƚŚĞƐĞ't^ ǁŽƵůĚĞǆƉůĂŝŶĂůĂƌŐĞƉĂƌƚŽĨƚŚĞŚĞƌŝƚĂďŝůŝƚǇĞƐƟŵĂƚĞƐ͘89_{dŚĞƐƵĐĐĞƐƐƌĂƚĞŽĨƚŚĞ't^} ǁĂƐĂƚƚŚĞďĞŐŝŶŶŝŶŐŵŽƐƚůǇůŝŵŝƚĞĚďǇƚŚĞƐĂŵƉůĞƐŝǌĞ͘,ŽǁĞǀĞƌǁŝƚŚƚŚĞƌĞĚƵĐƟŽŶŽĨ ŐĞŶŽƚǇƉĞĞǆƉĞŶƐĞƐ͕113_{ƚŚĞƐĂŵƉůĞƐŝǌĞƉĞƌƐƚƵĚǇŝŶĐƌĞĂƐĞĚ͕ƐƚĂƌƟŶŐĨƌŽŵϵϲĐĂƐĞƐĂŶĚ} ϱϬĐŽŶƚƌŽůƐĨŽƌƚŚĞĮƌƐƚ't^ƐƚƵĚǇĨŽĐƵƐŝŶŐŽŶŵĂĐƵůĂƌĚĞŐĞŶĞƌĂƟŽŶƐƚƵĚǇ͕71_{to 36,989} ƐĐŚŝǌŽƉŚƌĞŶŝĂƉĂƟĞŶƚƐĂŶĚϭϭϯ͕ϬϳϱĐŽŶƚƌŽůƐĂŵƉůĞƐĞŶĐŽŵƉĂƐƐŝŶŐĂŵĞƚĂͲĂŶĂůǇƐŝƐ't^

in 2014.114_{These high numbers of samples had already revealed over 14,000 variants that}

are associated to more than 700 traits by the end of 2013.115

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ĨŽƌ ƚŚĞ ǀĂƐƚ ŵĂũŽƌŝƚǇ ŽĨ ŶŽǀĞů ŝĚĞŶƟĮĞĚ ŐĞŶĞƟĐ ĨĂĐƚŽƌƐ͘116_{Secondly, contrary to what}

ǁĂƐĂŶƟĐŝƉĂƚĞĚ͖ƚŚĞŝĚĞŶƟĮĞĚĐŽŵŵŽŶǀĂƌŝĂŶƚƐǁĞƌĞŶŽƚĞǆƉůĂŝŶŝŶŐĂůĂƌŐĞƉĂƌƚŽĨƚŚĞ ŚĞƌŝƚĂďŝůŝƚǇ ĞƐƟŵĂƚĞƐ͕ ŝŵƉůǇŝŶŐ ƚŚĞ ĞǆŝƐƚĞŶĐĞ ŽĨ ĂĚĚŝƟŽŶĂů ƵŶĚŝƐĐŽǀĞƌĞĚ ŐĞŶĞƟĐ ƌŝƐŬ factors.117_{ƐĂŶĞǆĂŵƉůĞ͕ŚĞŝŐŚƚŚĞƌŝƚĂďŝůŝƚǇŝƐĞƐƟŵĂƚĞĚƚŽůŝĞďĞƚǁĞĞŶϴϬйĂŶĚϵϬй͘}118_A ŵƵůƟͲŝŶƐƟƚƵƟŽŶĂůĂƉƉƌŽĂĐŚŝŶϮϬϭϰƐƚƵĚǇŝŶŐϮϱϯ͕ϮϴϴŝŶĚŝǀŝĚƵĂůƐŝĚĞŶƟĮĞĚŽǀĞƌϰϮϯůŽĐŝ ĂƐƐŽĐŝĂƚĞĚƚŽŚĞŝŐŚƚďƵƚŽŶůǇĞǆƉůĂŝŶŝŶŐϮϬйŽĨƚŚĞŚĞƌŝƚĂďŝůŝƚǇ͘119 dŚĞ ŵŝƐƐŝŶŐ ŚĞƌŝƚĂďŝůŝƚǇ ĐŽƵůĚ ďĞ ĚƵĞ ƚŽ ƚŚĞ ĞǆŝƐƚĞŶĐĞ ŽĨ ŐĞŶƵŝŶĞ ĂƐƐŽĐŝĂƚĞĚ ^EWƐǁŝƚŚƚŽŽƐŵĂůůŝŶĚŝǀŝĚƵĂůǀĂƌŝĂŶƚĞīĞĐƚƐƚŽƉĂƐƐĐŽŶƐĞƌǀĂƟǀĞƐŝŐŶŝĮĐĂŶĐĞƚĞƐƚ͕ĂƐ

proposed by Yang et al.,120_{ŽƌƚŚĞĐŽŶƚƌŝďƵƟŽŶŽĨŽƚŚĞƌƚǇƉĞƐŽĨŐĞŶĞƟĐĨĂĐƚŽƌƐƚŚĂƚǁĞƌĞ}

ƵŶĂďůĞƚŽĚĞƚĞĐƚďǇ't^͘dŚĞůĂƩĞƌĞǆƉůĂŶĂƟŽŶƌĞƐƵůƚĞĚŝŶƚŚĞŶĞĞĚĨŽƌŶĞǆƚͲŐĞŶĞƌĂƟŽŶ

ƐĞƋƵĞŶĐŝŶŐ;E'^ͿŵĞƚŚŽĚƐ͕ĞŶĂďůŝŶŐƚŚĞƐƚƵĚǇŽĨƌĂƌĞǀĂƌŝĂŶƚƐ͘121_{/ƚǁĂƐŚǇƉŽƚŚĞƐŝǌĞĚ}

ƚŚĂƚƚŚĞŝĚĞŶƟĮĐĂƟŽŶŽĨƌĂƌĞĐĂƵƐĂůǀĂƌŝĂŶƚƐǁŽƵůĚŝŶĐƌĞĂƐĞƚŚĞƉƌŽƉŽƌƟŽŶŽĨŚĞƌŝƚĂďŝůŝƚǇ ƚŚĂƚĐŽƵůĚďĞĞǆƉůĂŝŶĞĚ͘&ƵƌƚŚĞƌŵŽƌĞ͕ďǇƐĞƋƵĞŶĐŝŶŐƚŚĞĨƵůůŐĞŶŽŵĞŽƌĞƐƐĞŶƟĂůƌĞŐŝŽŶƐ of the genome, the causal variants would be more easily detected, enabling a more ƐƚƌĂŝŐŚƞŽƌǁĂƌĚĂƉƉƌŽĂĐŚƚŽŝĚĞŶƟĨǇƚŚĞĐĂƵƐĂůĂŶĚďŝŽůŽŐŝĐĂůƌĞůĞǀĂŶƚǀĂƌŝĂŶƚ͘

ƵƌŝŶŐƚŚĞůĂƐƚĚĞĐĂĚĞ͕E'^ŚĂƐƌĞǀŽůƵƟŽŶŝǌĞĚƚŚĞŐĞŶŽŵŝĐƐƌĞƐĞĂƌĐŚĮĞůĚ͘E'^ ŽǀĞƌƌƵůĞĚ ƚŚĞ ĐŽŶǀĞŶƟŽŶĂů ^ĂŶŐĞƌͲďĂƐĞĚ ƐĞƋƵĞŶĐŝŶŐ ƚĞĐŚŶŝƋƵĞƐ͕ ĂƐ ŝƚ ǁĂƐ ĨĂƐƚĞƌ ĂŶĚ

ĐŚĞĂƉĞƌǁŚŝůĞŵĂŝŶƚĂŝŶŝŶŐĂŚŝŐŚƐĞŶƐŝƟǀŝƚǇ͘121_{E'^ƉƌŽĐĞƐƐĞƐŵŝůůŝŽŶƐŽĨEͲŵŽůĞĐƵůĞƐ}

simultaneously and is therefore called a massively parallel throughput method. The ŵĂŶŝĨĞƐƚĂƟŽŶ ŽĨ E'^ĐŚĂůůĞŶŐĞĚƚŚĞďŝŽŝŶĨŽƌŵĂƟĐƐĐŽŵŵƵŶŝƚǇ ƚŽĚĞǀĞůŽƉ ĐŽŵƉĞƚĞŶƚ ĂƉƉƌŽĂĐŚĞƐƚŽƐƚŽƌĞĂŶĚĂŶĂůǇǌĞƚŚĞŚƵŐĞĂŵŽƵŶƚŽĨĚĂƚĂƚŚĂƚǁĞƌĞƉƌŽĚƵĐĞĚďǇƚŚĞ sequencing machines.122_{ZĂǁƐĞƋƵĞŶĐĞĚĂƚĂŚĂƐƚŽŐŽƚŚƌŽƵŐŚŵƵůƟƉůĞĂŶĂůǇƐĞƐƐƚĞƉƐ} ĞŶĐŽŵƉĂƐƐŝŶŐƌĞĂĚƋƵĂůŝƚǇĐŽŶƚƌŽů͕ĂůŝŐŶŵĞŶƚŽĨƌĞĂĚƐƚŽƌĞĨĞƌĞŶĐĞŐĞŶŽŵĞ͕ƌĞĐĂůŝďƌĂƟŽŶ ŽĨ ĂůŝŐŶĞĚ ƌĞĂĚƐ ĂŶĚ ǀĂƌŝĂŶƚƐ ĐĂůůŝŶŐ͕ ŝŶĐůƵĚŝŶŐ ƐŵĂůů ŝŶƐĞƌƟŽŶƐͬĚĞůĞƟŽŶƐ ;ŝŶĚĞůƐͿ ĂŶĚ ƐŝŶŐůĞ ŶƵĐůĞŽƟĚĞ ǀĂƌŝĂŶƚƐ ;^EsƐͿ͘ ƐƉĞĐŝĂůůǇ ǁŚĞŶ ƐŝŵƵůƚĂŶĞŽƵƐůǇ ĐĂůůŝŶŐ ǀĂƌŝĂŶƚƐ ĨŽƌ ŚƵŶĚƌĞĚƐŽƌƚŚŽƵƐĂŶĚƐŽĨƐĂŵƉůĞƐ͕ĂĐŽŵƉƵƚĞƌĐůƵƐƚĞƌŝƐƌĞƋƵŝƌĞĚ͘DĂŶǇĚŝīĞƌĞŶƚƚŽŽůƐ ŚĂǀĞďĞĞŶĚĞǀĞůŽƉĞĚƚŽĚĞĂůǁŝƚŚƚŚĞƐĞĂŶĂůǇƐĞƐƐƚĞƉƐ͕ĂŝŵŝŶŐƚŽĂŶĂůǇǌĞƚŚĞĚĂƚĂŝŶƚŚĞ

fastest way while maintaining the highest quality.123,124

^ĞƋƵĞŶĐŝŶŐƚŚĞĨƵůůŐĞŶŽŵĞďǇE'^ǁĂƐƚŚĞŵŽƐƚĂƩƌĂĐƟǀĞĂƉƉƌŽĂĐŚ͕ĂƐǇŽƵ ƐĞƋƵĞŶĐĞ ĞǀĞƌǇ ŶƵĐůĞŽƟĚĞ ĂŶĚ ƚŚĞƌĞďǇ ŝŶĐƌĞĂƐĞ ƚŚĞ ůŝŬĞůŝŚŽŽĚ ƚŽ ƵŶĐŽǀĞƌ ƚŚĞ ĐĂƵƐĂů ǀĂƌŝĂŶƚ͘ ,ŽǁĞǀĞƌ͕ ƚŚĞ ĐŽƐƚƐ ƚŽ ƉĞƌĨŽƌŵ ǁŚŽůĞͲŐĞŶŽŵĞ ƐĞƋƵĞŶĐŝŶŐ ǁĞƌĞ ĞǆĐĞƐƐŝǀĞůǇ ŚŝŐŚ Ăƚ ƚŚĞ ďĞŐŝŶŶŝŶŐ ŽĨ ƚŚĞ E'^ ĞƌĂ͕ ĞƐƉĞĐŝĂůůǇ ĨŽƌ ůĂƌŐĞͲƐĐĂůĞ ĐŽŚŽƌƚƐ͘ ƌŽƵŶĚ ϮϬϬϴ͕

the costs for a single genome were around 10 million dollar.125_{As a comparison, anno}

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linkage analyses, as was the case for the discovery of C9orf72 ĨŽƌ&dͲ>^͘128,129_Another

ŽƉƟŽŶŝƐt^͕ǁŚŝĐŚŝƐƐƚĂŶĚĂƌĚĐŽŵŵĞƌĐŝĂůůǇĂǀĂŝůĂďůĞďǇĞǀĞƌǇƐĞƋƵĞŶĐŝŶŐƚĞĐŚŶŽůŽŐǇ ĐŽŵƉĂŶǇ͘ƐƚŚĞĐŽƐƚƐƉĞƌƚŽƚĂůŐĞŶŽŵĞǁĞƌĞƐƟůůƌĞůĂƟǀĞůǇŚŝŐŚ;хΨϱ͕ϬϬϬͿƚŚĞŵŽŵĞŶƚ this PhD thesis was started in 2011, it was decided to use WES to study all coding regions ŽĨƚŚĞŐĞŶŽŵĞŝŶĂƌĞůĂƟǀĞůǇƵŶďŝĂƐĞĚĨĂƐŚŝŽŶ͘

t^ ĂŝŵƐ ƚŽ ƚĂƌŐĞƚ ĞǀĞƌǇ ĞǆŽŶ ŽĨ Ăůů ƉƌŽƚĞŝŶ ĐŽĚŝŶŐ ŐĞŶĞƐ͘130_{ǆŽŶƐ ĂƌĞ ƚŚĞ}

ĐŽŵƉŽŶĞŶƚƐŽĨƚŚĞŐĞŶĞƚŚĂƚĂƌĞƚƌĂŶƐĐƌŝďĞĚŝŶƚŽŵZEĂŶĚĞǀĞŶƚƵĂůůǇƚƌĂŶƐůĂƚĞĚŝŶƚŽ amino acids which are the building blocks of all proteins in the human body. By sequencing ĂůůĐŽĚŝŶŐƌĞŐŝŽŶƐŽĨƚŚĞŐĞŶŽŵĞǁĞĂŶƟĐŝƉĂƚĞĚƚŽŝŶĐƌĞĂƐĞƚŚĞĐŚĂŶĐĞƚŽĚĞƚĞĐƚĂǀĂƌŝĂŶƚ ƚŚĂƚŵŝŐŚƚďĞĚĂŵĂŐŝŶŐĨŽƌƚŚĞĨƵŶĐƟŽŶŽĨƚŚĞĐŽƌƌĞƐƉŽŶĚŝŶŐƉƌŽƚĞŝŶ͘131,132_{Variants in} ĨƵŶĐƟŽŶĂůĚŽŵĂŝŶƐŽĨƚŚĞƉƌŽƚĞŝŶĐŽƵůĚĨŽƌŝŶƐƚĂŶĐĞŝŶƚĞƌƌƵƉƚŝƚƐƉŚǇƐŝĐĂůŝŶƚĞƌĂĐƟŽŶƐǁŝƚŚ ŽƚŚĞƌƉƌŽƚĞŝŶƐ͘KƌǀĂƌŝĂŶƚƐĐŚĂŶŐŝŶŐƚŚĞĂŵŝŶŽĂĐŝĚ͕ƚŚĞŶŽŶƐǇŶŽŶǇŵŽƵƐǀĂƌŝĂŶƚƐ͕ĐŽƵůĚ ŚĂǀĞĂŶĞīĞĐƚŽŶƚŚĞĨŽůĚŝŶŐďĞŚĂǀŝŽƌŽĨƚŚĞƉƌŽƚĞŝŶ͘sĂƌŝŽƵƐĞǆŽŶŝĐǀĂƌŝĂŶƚĐĂƚĞŐŽƌŝĞƐ ĞǆŝƐƚǁŚŝĐŚŚĂǀĞĚŝīĞƌĞŶƚŵĂŐŶŝƚƵĚĞƐŽĨĞīĞĐƚŽŶƚŚĞŐĞŶĞ͛ƐĨƵŶĐƟŽŶ;ŽǆĂŶĚ&ŝŐƵƌĞ 2). dŽƉƌĞĚŝĐƚƚŚĞĨƵŶĐƟŽŶĂůĞīĞĐƚŽĨĞǆŽŶŝĐǀĂƌŝĂŶƚƐ͕ƚŚĞďŝŽŝŶĨŽƌŵĂƟĐƐĮĞůĚŚĂƐ ĚĞǀĞůŽƉĞĚ ǀĂƌŝŽƵƐ ĂůŐŽƌŝƚŚŵƐ ǁŚŝĐŚ ĐŽŶƐŝĚĞƌ ďŝŽůŽŐŝĐĂů ŵĞƚƌŝĐƐ ŝŶĐůƵĚŝŶŐ ĐŽŶƐĞƌǀĂƟŽŶ

scores (e.g. PhyloP133_{Ϳ͕ƚƌĂŶƐĐƌŝƉƟŽŶŝŶĨŽƌŵĂƟŽŶ;Ğ͘Ő͘ƉŽƐŝƟŽŶǁŝƚŚƌĞĨĞƌĞŶĐĞƚŽĞǆŽŶͲŝŶƚƌŽŶ}

boundaries134_{Ϳ͕ƉƌŽƚĞŝŶůĞǀĞůƐĐŽƌĞƐ;Ğ͘Ő͘^/&d}135_{ͿĂŶĚƌĞŐƵůĂƚŽƌǇŝŶĨŽƌŵĂƟŽŶ;Ğ͘Ő͘ƌĞŐŝŽŶƐ}

ŽĨEĂƐĞ/ŚǇƉĞƌƐĞŶƐŝƟǀŝƚǇ136_{Ϳ͘dŚĞŐĞŶĞƌĂůĐŽŶƐĞŶƐƵƐŝƐƚŽƵƐĞĂŶŶŽƚĂƟŽŶĂůŐŽƌŝƚŚŵƐƐƵĐŚ}

ĂƐƚŚĞŽŵďŝŶĞĚŶŶŽƚĂƟŽŶʹĞƉĞŶĚĞŶƚĞƉůĞƟŽŶ;Ϳ137_{ĨƌĂŵĞǁŽƌŬŽƌ&ƵŶĐƟŽŶĂů}

ŶĂůǇƐŝƐ ƚŚƌŽƵŐŚ ,ŝĚĚĞŶ DĂƌŬŽǀ DŽĚĞůƐ ;&d,DDͲD<>Ϳ138_{, which aim to incorporate}

ĂůůƚŚĞĂƐƉĞĐƚƐŽĨƉƌĞǀŝŽƵƐƉƌĞĚŝĐƟŽŶĂůŐŽƌŝƚŚŵƐ͕ǁŚŝůĞĐŽǀĞƌŝŶŐƚŚĞƚŽƚĂůŐĞŶŽŵĞ͘dŚĞ ĂĚǀĂŶƚĂŐĞ ŽĨ ĂŶĚ &d,DDͲD<>͕ ŽǀĞƌ ƚŚĞ ŽůĚĞƌ ƉƌĞĚŝĐƟŽŶ ĂůŐŽƌŝƚŚŵƐ ;ůŝŬĞ ^/&d ĂŶĚWŽůǇƉŚĞŶͿ͕ŝƐƚŚĂƚƚŚĞƉƌĞĚŝĐƟŽŶƐŚĂǀĞďĞĞŶĐĂůĐƵůĂƚĞĚĨŽƌĞǀĞƌǇƉŽƐƐŝďůĞŶƵĐůĞŽƟĚĞ ĐŚĂŶŐĞŝŶƚŚĞŐĞŶŽŵĞ͕ŝŶĐůƵĚŝŶŐĞǆŽŶŝĐĐŚĂŶŐĞƐŶŽƚĂīĞĐƟŶŐƚŚĞĐŽƌƌĞƐƉŽŶĚŝŶŐĂŵŝŶŽ acid or non-coding variants located in intronic and intergenic regions.

dŚĞĮƌƐƚƐƵĐĐĞƐƐĨƵůt^ƐƚƵĚǇǁĂƐƉƵďůŝƐŚĞĚŝŶϮϬϭϭ͕ŝĚĞŶƟĨǇŝŶŐDHODH as the

causal gene for the rare Mendelian disorder Miller syndrome.139_{&ŽƵƌĂīĞĐƚĞĚŝŶĚŝǀŝĚƵĂůƐ}

ĨƌŽŵƚŚƌĞĞĚŝīĞƌĞŶƚĨĂŵŝůŝĞƐŚĂƌďŽƌĞĚĚŝīĞƌĞŶƚƌĂƌĞŵƵƚĂƟŽŶƐƚŚĂƚǁĞƌĞĂůůƉƌĞĚŝĐƚĞĚƚŽ ďĞƉĂƚŚŽŐĞŶŝĐǁŝƚŚŝŶƚŚĞƐĂŵĞŐĞŶĞ͘DĂŶǇŽƵƚƐƚĂŶĚŝŶŐĞǆŽŵĞƐƚƵĚŝĞƐĨŽůůŽǁĞĚ͕ŵŽƐƚůǇ

ĨŽĐƵƐŝŶŐŽŶDĞŶĚĞůŝĂŶĚŝƐŽƌĚĞƌƐďǇĞǆĂŵŝŶŝŶŐĨĂŵŝůŝĂůĐĂƐĞƐ͘140_{WES mainly focuses on}

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Žǆ͘ǆŽŶŝĐǀĂƌŝĂŶƚƚǇƉĞƐ >ŽƐƐͲŽĨͲĨƵŶĐƟŽŶǀĂƌŝĂŶƚƐ;>Ž&Ϳ LoF ǀĂƌŝĂŶƚƐ ĂƌĞ ĂŶƟĐŝƉĂƚĞĚ ƚŽ ŚĂǀĞ Ă ŚŝŐŚ ŝŵƉĂĐƚ ďǇ ĚŝƐƌƵƉƟŶŐ ƚŚĞ ƉƌŽƚĞŝŶͲĐŽĚŝŶŐ ŐĞŶĞƐ͕ ƚŚĞƌĞĨŽƌĞ ĂůƐŽ ĐĂůůĞĚ ĚŝƐƌƵƉƟǀĞ ǀĂƌŝĂŶƚƐ͘ dŚŝƐ ƐƵďƐĞƚ ŽĨ ǀĂƌŝĂŶƚƐ ŝƐ ĂƐƐƵŵĞĚ ƚŽ ĚŝŵŝŶŝƐŚ ƚŚĞ ĐŽƌƌĞƐƉŽŶĚŝŶŐŐĞŶĞͲĞǆƉƌĞƐƐŝŽŶ͕ƚŚĞƌĞďǇĚĞĐƌĞĂƐŝŶŐƚŚĞĨƵŶĐƟŽŶŽĨƚŚĞŐĞŶĞ͘dŚƌĞĞƚǇƉĞƐŽĨ >Ž&ǀĂƌŝĂŶƚƐĞǆŝƐƚ͗ϭͿƐƚŽƉŐĂŝŶͬƐƚŽƉůŽƐƐǀĂƌŝĂŶƚƐ͕ϮͿƐƉůŝĐŝŶŐǀĂƌŝĂŶƚƐĂŶĚϯͿĨƌĂŵĞƐŚŝŌŝŶĚĞůƐ͘ dŚĞĮƌƐƚ>Ž&ƚǇƉĞŝŶŇƵĞŶĐĞƐƚŚĞƉŽƐŝƟŽŶŽĨƚŚĞƐƚŽƉĐŽĚŽŶ͕ǁŚŝĐŚŝƐƚŚĞŵĂƌŬĞƌĨŽƌĂE ƉŽůǇŵĞƌĂƐĞƚŽƚĞƌŵŝŶĂƚĞƚŚĞƚƌĂŶƐĐƌŝƉƟŽŶƉƌŽĐĞƐƐ͘^ƉůŝĐŝŶŐǀĂƌŝĂŶƚƐĂƌĞĐůŽƐĞƚŽƚŚĞŝŶƚƌŽŶͲĞǆŽŶ ďŽƵŶĚĂƌŝĞƐ͕ƚŚĞƌĞĨŽƌĞƉƌĞƐƵŵĂďůǇŝŶŇƵĞŶĐŝŶŐƚŚĞƐƉůŝĐĞĂĐƟǀŝƚǇŽĨƚŚĞƚƌĂŶƐĐƌŝƉƚ͘&ƌĂŵĞƐŚŝŌƐ͕ ǁŚŝĐŚĐĂƵƐĞĂĚŝīĞƌĞŶƚĂŵŝŶŽĂĐŝĚƐĞƋƵĞŶĐĞĨƌŽŵƚŚĞƉŽƐŝƟŽŶǁŚĞƌĞƚŚĞŝŶĚĞůŽĐĐƵƌƐ͕ŽŌĞŶ ƌĞƐƵůƚŝŶĂƐƚŽƉĐŽĚŽŶƌĞůĂƟǀĞůǇĐůŽƐĞƚŽƐƚĂƌƚŽĨƚŚĞĨƌĂŵĞƐŚŝŌ͘/ŶŐĞŶĞƌĂů͕>Ž&ǀĂƌŝĂŶƚƐĂƌĞ ƌĂƌĞŝŶƚŚĞŚƵŵĂŶƉŽƉƵůĂƟŽŶĂƐƐƚƌŽŶŐƉƵƌŝĨǇŝŶŐƐĞůĞĐƟŽŶĂŐĂŝŶƐƚĚĞůĞƚĞƌŝŽƵƐǀĂƌŝĂŶƚƐŝƐĂƚ play.141,142 Nonsynonymous variants

These amino acid changing variants are furthermore called missense variants. Although such ǀĂƌŝĂŶƚƐŵĂǇŚĂƌŵƚŚĞĨƵŶĐƟŽŶŽĨƚŚĞŐĞŶĞ͕ŵĂŶǇĂƌĞĂůƐŽďĞŶŝŐŶ͘dŚĞďĞŶŝŐŶŶŽŶƐǇŶŽŶǇŵŽƵƐ ǀĂƌŝĂŶƚƐ ĂƌĞ ŽŌĞŶ ĐŽŵŵŽŶ ŝŶ ƚŚĞ ŐĞŶĞƌĂů ƉŽƉƵůĂƟŽŶ ĂƐ ŶĂƚƵƌĂů ƐĞůĞĐƟŽŶ ƚŽůĞƌĂƚĞƐ ŶŽŶͲ damaging variants.142_{DƵůƟƉůĞĞĸĐŝĞŶƚďŝŽŝŶĨŽƌŵĂƟĐƐƐƚƌĂƚĞŐŝĞƐŚĂǀĞďĞĞŶĚĞǀĞůŽƉĞĚƚŽũƵĚŐĞ} ƚŚĞĨƵŶĐƟŽŶĂůŝƚǇŽĨǀĂƌŝĂŶƚƐ͕ŝŶĐůƵĚŝŶŐƚŚĞŶŽŶƐǇŶŽŶǇŵŽƵƐŽŶĞƐ͘dŚĞƉƌĞĚŝĐƟŽŶƐĂƌĞďĂƐĞĚŽŶ ĐŽŶƐĞƌǀĂƟŽŶƐĐŽƌĞƐ;Ğ͘Ő͘WŚǇůŽW133_{Ϳ͕ƚƌĂŶƐĐƌŝƉƟŽŶŝŶĨŽƌŵĂƟŽŶ;Ğ͘Ő͘ƉŽƐŝƟŽŶǁŝƚŚƌĞĨĞƌĞŶĐĞƚŽ} ĞǆŽŶͲŝŶƚƌŽŶďŽƵŶĚĂƌŝĞƐ134_{Ϳ͕ƉƌŽƚĞŝŶůĞǀĞůƐĐŽƌĞƐ;Ğ͘Ő͘^/&d}135_{ͿĂŶĚƌĞŐƵůĂƚŽƌǇŝŶĨŽƌŵĂƟŽŶ;Ğ͘Ő͘}

ƌĞŐŝŽŶƐŽĨEĂƐĞ/ŚǇƉĞƌƐĞŶƐŝƟǀŝƚǇ136_{). These algorithms are required to select the variants that}

have a high likelihood to be involved in the disease pathogenesis.

EŽŶͲĨƌĂŵĞƐŚŝŌŝŶĚĞůƐ dŚŝƐĐĂƚĞŐŽƌǇĞŶĐŽŵƉĂƐƐĞƐƚŚĞƐŵĂůůŝŶƐĞƌƟŽŶƐĂŶĚĚĞůĞƟŽŶƐƚŚĂƚĂƌĞǁŝƚŚŝŶƚŚĞƌĞĂĚŝŶŐĨƌĂŵĞ͘ EŽŶͲĨƌĂŵĞƐŚŝŌŝŶĚĞůƐĂīĞĐƚƚŚƌĞĞĂĚũĂĐĞŶƚůǇůŽĐĂƚĞĚŶƵĐůĞŽƟĚĞƐ͕ƚŚĞƌĞĨŽƌĞŽŶůǇĐŚĂŶŐŝŶŐƚŚĞ ĂŵŝŶŽĂĐŝĚƐĂƚƚŚĂƚĞǆĂĐƚƉŽƐŝƟŽŶ͘143_{ŐĂŝŶ͕ƐƵĐŚǀĂƌŝĂŶƚƐŚĂǀĞďĞŶŝŐŶŽƌŚĂƌŵĨƵůĞīĞĐƚƐĂŶĚ} ďŝŽŝŶĨŽƌŵĂƟĐƐĨƵŶĐƟŽŶĂůƉƌĞĚŝĐƟŽŶĂůŐŽƌŝƚŚŵƐĂƌĞĂƉƉůŝĞĚƚŽĚĞƚĞƌŵŝŶĞƚŚĞĚĞůĞƚĞƌŝŽƵƐŶĞƐƐ͘ Synonymous variants ǆŽŶŝĐƐǇŶŽŶǇŵŽƵƐǀĂƌŝĂŶƚƐ͕ĂůƐŽĐĂůůĞĚƐŝůĞŶƚŵƵƚĂƟŽŶƐ͕ĂƌĞƚƌĂĚŝƟŽŶĂůůǇĞǆƉĞĐƚĞĚƚŽŚĂǀĞůŽǁ ŝŵƉĂĐƚŽŶƚŚĞĨƵŶĐƟŽŶŽĨĂŐĞŶĞ͕ĐŽŵƉĂƌĂďůĞƚŽŝŶƚƌŽŶŝĐ͕ϯ͛ĂŶĚϱ͛hdZǀĂƌŝĂŶƚƐ͕ĂƐƚŚĞĂŵŝŶŽ acid is preserved. However, more recent studies show that such variants, changing the codon ďƵƚŶŽƚƚŚĞĂŵŝŶŽĂĐŝĚ͕ĐŽƵůĚŚĂǀĞƐŝŐŶŝĮĐĂŶƚĞīĞĐƚƐŽŶƐƵďƐƚƌĂƚĞƐƉĞĐŝĮĐŝƚǇŽƌƚƌĂŶƐůĂƟŽŶ

speed.144,145_{^ŽŵĞ ĨƵŶĐƟŽŶĂů ƉƌĞĚŝĐƟŽŶ ĂůŐŽƌŝƚŚŵƐ ;Ğ͘Ő͘ ĂŶĚ &d,DDͲD<>Ϳ ĐĂůĐƵůĂƚĞ}

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ĂŐŐƌĞŐĂƚĞƌĂƌĞǀĂƌŝĂŶƚƐƉĞƌŐĞŶĞĂŶĚƚĞƐƚĨŽƌƚŚĞĐŽŵďŝŶĞĚĂƐƐŽĐŝĂƟŽŶƚŽĂƚƌĂŝƚ͘ůƚŚŽƵŐŚ ƉŽƉƵůĂƟŽŶĂƐƐŽĐŝĂƟŽŶƐƚƵĚŝĞƐƐĞĞŵĞĚƚŚĞŶĞǆƚůŽŐŝĐĂůƐƚĞƉ͕ƚŚĞĂĐĐŽŵƉĂŶŝĞĚŝƐƐƵĞƐǁĞƌĞ ƵŶĚĞƌĞƐƟŵĂƚĞĚ͘146 ƐĨŽƌƚƌĂĚŝƟŽŶĂů't^͕ǀĞƌǇůĂƌŐĞƐĂŵƉůĞƐŝǌĞƐĂƌĞƌĞƋƵŝƌĞĚ͕ƉĂƌƟĐƵůĂƌůǇǁŚĞŶ ĨŽĐƵƐŝŶŐŽŶĐŽŵƉůĞǆĚŝƐĞĂƐĞƐĐĂƵƐĞĚďǇƌĂƌĞǀĂƌŝĂŶƚƐǁŝƚŚŵŝůĚĞīĞĐƚƐ͘&ƵƌƚŚĞƌŵŽƌĞ͕ƌĂƌĞ ǀĂƌŝĂŶƚĂŐŐƌĞŐĂƟŽŶƚĞƐƚƐĂƌĞŵŽƌĞƐĞŶƐŝƟǀĞƚŽĐŽŶĨŽƵŶĚŝŶŐĨĂĐƚŽƌƐƐƵĐŚĂƐƉŽƉƵůĂƟŽŶ ƐƚƌĂƟĮĐĂƟŽŶ͕ĞƐƉĞĐŝĂůůǇĐŽŶƐŝĚĞƌŝŶŐƚŚĞĚŝīĞƌĞŶĐĞŝŶŶƵŵďĞƌŽĨƌĂƌĞǀĂƌŝĂŶƚƐŝŶĚŝīĞƌĞŶƚ

ĞƚŚŶŝĐƉŽƉƵůĂƟŽŶƐ͘147_{Another important aspect to consider when performing rare variant}

ĂƐƐŽĐŝĂƟŽŶƚĞƐƚŝƐǁŚŝĐŚƚǇƉĞŽĨǀĂƌŝĂŶƚƐƚŽŝŶĐůƵĚĞ͘hůƟŵĂƚĞůǇ͕ŽŶĞǁŽƵůĚƉƌĞĨĞƌƚŽƚĞƐƚ ŽŶůǇƚŚŽƐĞǀĂƌŝĂŶƚƐƚŚĂƚŚĂǀĞĂĚĞůĞƚĞƌŝŽƵƐĞīĞĐƚŽŶƚŚĞĨƵŶĐƟŽŶŽĨĂŐĞŶĞĂŶĚĞǆĐůƵĚĞ ďĞŶŝŐŶǀĂƌŝĂŶƚƐƚŚĂƚĚŝůƵƚĞĂŶĂƐƐŽĐŝĂƟŽŶƐŝŐŶĂů͘ǇŽŶůǇƐƚƵĚǇŝŶŐǀĂƌŝĂŶƚƐďĞůŽǁĂĐĞƌƚĂŝŶ ƌĂƌĞ ŵŝŶŽƌ ĂůůĞůĞ ĨƌĞƋƵĞŶĐǇ ;D&Ϳ ĐƵƚŽī ;ĚĂŵĂŐŝŶŐ ǀĂƌŝĂŶƚƐ ĂƌĞ ĞǆƉĞĐƚĞĚ ƚŽ ŚĂǀĞ Ă ůŽǁĞƌD&ŝŶƚŚĞŐĞŶĞƌĂůƉŽƉƵůĂƟŽŶĚƵĞƚŽŶĂƚƵƌĂůƐĞůĞĐƟŽŶͿĂŶĚǀĂƌŝĂŶƚƐƉƌĞĚŝĐƚĞĚƚŽ ďĞĚĂŵĂŐŝŶŐďǇĨƵŶĐƟŽŶĂůƉƌĞĚŝĐƟŽŶĂůŐŽƌŝƚŚŵƐ͕ƚŚĞƐĞůĞĐƟŽŶŽĨĨƵŶĐƟŽŶĂůǀĂƌŝĂŶƚƐŝƐ

ŚǇƉŽƚŚĞƐŝǌĞĚƚŽďĞŵĂǆŝŵŝǌĞĚ͘148,149_{Another possibility to boost power is to aggregate}

ǀĂƌŝĂŶƚƐŽǀĞƌƐĞƚƐŽĨŐĞŶĞƐďĞůŽŶŐŝŶŐƚŽƐŝŵŝůĂƌďŝŽůŽŐŝĐĂůƉĂƚŚǁĂǇƐ͕ŝŶĐƌĞĂƐŝŶŐƚŚĞĞīĞĐƚ ƐŝǌĞďǇƚŚĞũŽŝŶƚŶƵŵďĞƌŽĨǀĂƌŝĂŶƚƐƚŚĂƚĂƌĞƚĞƐƚĞĚ͘148 ůƚŚŽƵŐŚ ŵĂŶǇ ŽĨ ƚŚĞ ĂďŽǀĞͲŵĞŶƟŽŶĞĚ ĂƐƉĞĐƚƐ ƐŚŽƵůĚ ďĞ ĐŽŶƐŝĚĞƌĞĚ ǁŚĞŶ ƉĞƌĨŽƌŵŝŶŐ ŚŝŐŚͲƋƵĂůŝƚǇ ĂƐƐŽĐŝĂƟŽŶ ƚĞƐƚƐ ǁŝƚŚ t^ ĚĂƚĂ ŝŶ ƉŽƉƵůĂƟŽŶƐ͕ ĨĞǁ ƐƚƵĚŝĞƐ ŐĞŶĞƌĂƚĞĚǀĂůƵĂďůĞƌĞƐƵůƚƐďǇƉƌŽƉĞƌƐƚƵĚǇĚĞƐŝŐŶ͘t^ƐƚƵĚǇĨŽĐƵƐŝŶŐŽŶƐĐŚŝǌŽƉŚƌĞŶŝĂ͕ ŝŶĐůƵĚŝŶŐŽǀĞƌϱ͕ϬϬϬƐĂŵƉůĞƐǁŝƚŚďĂůĂŶĐĞĚĐĂƐĞͲĐŽŶƚƌŽůĚŝƐƚƌŝďƵƟŽŶ͕ŝĚĞŶƟĮĞĚĂƉŽůǇŐĞŶŝĐ ďƵƌĚĞŶŽĨƌĂƌĞ>Ž&ǀĂƌŝĂŶƚƐŝŶƐĞǀĞƌĂůŐĞŶĞͲƐĞƚƐ͘150_{ĞƐŝĚĞƐƐŚŽǁŝŶŐƚŚĞĐŽŶƚƌŝďƵƟŽŶŽĨ} ƌĂƌĞƌŝƐŬĨĂĐƚŽƌƐŝŶŐĞŶĞƐŝŶǀŽůǀĞĚŝŶĐĂůĐŝƵŵŝŽŶĐŚĂŶŶĞůƐĂŶĚƐŝŐŶĂůŝŶŐĐŽŵƉůĞǆĞƐŽĨƚŚĞ ƉŽƐƚƐǇŶĂƉƟĐĚĞŶƐŝƚǇ͕ƚŚĞǇŵŽƌĞŽǀĞƌƐŚŽǁĞĚƚŚĂƚƉƌŽƉĞƌt^ƐƚƵĚǇĚĞƐŝŐŶĞŶĂďůĞƐƚŚĞ ŝĚĞŶƟĮĐĂƟŽŶŽĨƌĂƌĞƌŝƐŬĂůůĞůĞƐŝŶƉŽƉƵůĂƟŽŶͲďĂƐĞĚƌĞƐĞĂƌĐŚ͘ƐĞĐŽŶĚƉŽƉƵůĂƟŽŶͲďĂƐĞĚ t^ĂƐƐŽĐŝĂƟŽŶƐƚƵĚǇ;Ϯ͕ϴϲϵĂŵǇŽƚƌŽƉŚŝĐůĂƚĞƌĂůƐĐůĞƌŽƐŝƐƉĂƟĞŶƚƐĂŶĚϲ͕ϰϬϱĐŽŶƚƌŽůƐͿ discovered a novel risk gene, TBK1͕ďǇƌƵŶŶŝŶŐĂƐƚĂŶĚĂƌĚĂŐŐƌĞŐĂƟŽŶĂƐƐŽĐŝĂƟŽŶŵĞƚŚŽĚ

that collapses rare variants for every gene of the genome.151_{Both these studies highlight}

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processes, 153_{Type 2 Diabetes}154_{ĂŶĚƐĐŚŝǌŽƉŚƌĞŶŝĂ͘}155_{ƐƉĞĐŝĮĐĞǆŽŵĞĂƌƌĂǇŽĨ/ůůƵŵŝŶĂ}

ŚĂƐ ďĞĞŶ ĐƌĞĂƚĞĚ ŝŶ ƚŚĞ ĐŽŶƚĞǆƚ ŽĨ ŐĞŶĞƟĐ ĨĂĐƚŽƌƐ ĐŽŶƚƌŝďƵƟŶŐ ƚŽ ŶĞƵƌŽĚĞŐĞŶĞƌĂƟǀĞ diseases.156_{/ŶĂĚĚŝƟŽŶƚŽƚŚĞƐƚĂŶĚĂƌĚ/ůůƵŵŝŶĂĞǆŽŵĞďĂĐŬďŽŶĞŽĨΕϮϰϬ͕ϬϬϬǀĂƌŝĂŶƚƐ͕ƚŚŝƐ} EĞƵƌŽyĞǆŽŵĞĂƌƌĂǇĂůƐŽŝŶĐůƵĚĞƐΕϮϱ͕ϬϬϬǀĂƌŝĂŶƚƐĂƐƐŽĐŝĂƚĞĚƚŽŶĞƵƌŽůŽŐŝĐĂůĚŝƐĞĂƐĞƐ͘ dŚŝƐĐŚŝƉĞŶĂďůĞƐĞǆŽŵĞĂƐƐŽĐŝĂƟŽŶƐƚƵĚŝĞƐƚŚĂƚĂƌĞĞŶƌŝĐŚĞĚĨŽƌǀĂƌŝĂŶƚƐŝŵƉŽƌƚĂŶƚĨŽƌ ŶĞƵƌŽĚĞŐĞŶĞƌĂƟǀĞƉƌŽĐĞƐƐĞƐ͘ůƚŚŽƵŐŚĞǆŽŵĞĐŚŝƉƐĂƌĞďĞŶĞĮĐŝĂůŝŶƚĞƌŵƐŽĨƐĂŵƉůĞ ƐŝǌĞƚŚĞǇŚĂǀĞƚŚĞĚŝƐĂĚǀĂŶƚĂŐĞƚŚĂƚŶŽǀĞůǀĂƌŝĂŶƚƐƌĞŵĂŝŶƵŶĐŽǀĞƌĞĚĂŶĚŝƐƚŚĞƌĞĨŽƌĞ ůŝŵŝƚĞĚƚŽŬŶŽǁŶŐĞŶĞƟĐĨĂĐƚŽƌƐ͘tŚĞŶŵŽŶĞǇŝƐŶŽƚĂůŝŵŝƟŶŐĨĂĐƚŽƌŽƌĐŽŚŽƌƚƐǁŝƚŚ ƐŵĂůůĞƌƐĂŵƉůĞƐŝǌĞƐĂƌĞďĞŝŶŐƐƚƵĚŝĞĚ͕t^ŝƐƚŚĞƉƌĞĨĞƌƌĞĚŽƉƟŽŶ͘ /ŶƚĞƌŶĂƟŽŶĂůWĂƌŬŝŶƐŽŶ͛ƐŝƐĞĂƐĞ'ĞŶŽŵŝĐƐŽŶƐŽƌƟƵŵ īĞĐƟǀĞŐĞŶĞƌĂƟŽŶŽĨůĂƌŐĞͲƐĐĂůĞt^ĚĂƚĂƐĞƚƐ͕ǁŚŝĐŚĂƌĞƌĞƋƵŝƌĞĚĨŽƌĂĚĞƋƵĂƚĞƐƚĂƟƐƟĐĂů ƚĞƐƟŶŐŽĨŐĞŶĞƟĐĂƐƐŽĐŝĂƟŽŶƐ͕ŝƐĚĞƉĞŶĚŝŶŐŽŶũŽŝŶĞĚĨŽƌĐĞƐŽĨŵƵůƟƉůĞƐĐŝĞŶƟĮĐĞŶƟƟĞƐ ;Ğ͘Ő͘ŝŶƐƟƚƵƚĞƐ͕ƵŶŝǀĞƌƐŝƟĞƐ͕ĨƵŶĚƐ͕ĞƚĐ͘Ϳ͘ŽŶƐŽƌƟĂĂƌĞĨƵƌƚŚĞƌŵŽƌĞŽĨŐƌĞĂƚǀĂůƵĞƚŽƐŚĂƌĞ ƚŚĞŚŝŐŚĞǆƉĞƌŝŵĞŶƚĂůĞǆƉĞŶƐĞƐ͘&ŽƌŐĞŶĞƟĐƌĞƐĞĂƌĐŚŝŶW͕ĂǁŽƌůĚǁŝĚĞĐŽůůĂďŽƌĂƟŽŶ ǁĂƐƐƚĂƌƚĞĚŝŶϮϬϬϳďĞƚǁĞĞŶŐĞŶĞƟĐƐĐŝĞŶƟƐƚƐĨƌŽŵƚŚĞhŶŝƚĞƐ^ƚĂƚĞƐ͕hŶŝƚĞĚ<ŝŶŐĚŽŵ͕ dŚĞ EĞƚŚĞƌůĂŶĚƐ͕ &ƌĂŶĐĞ ĂŶĚ 'ĞƌŵĂŶǇ͕ ĨŽƌŵŝŶŐ ƚŚĞ /ŶƚĞƌŶĂƟŽŶĂů WĂƌŬŝŶƐŽŶ͛Ɛ ŝƐĞĂƐĞ 'ĞŶŽŵŝĐƐ ŽŶƐŽƌƟƵŵ ;/W'͖ ǁǁǁ͘ƉĚŐĞŶĞƟĐƐ͘ŽƌŐͿ͘ dŚĞ ŝŶŝƟĂů ŐŽĂů ĞŶĐŽŵƉĂƐƐĞĚ ƚŚĞ ƉĞƌĨŽƌŵĂŶĐĞ ŽĨ Ă 't^͕ ƌĞĂĐŚŝŶŐ Ă ƐĂŵƉůĞ ƐŝǌĞ ĂůůŽǁŝŶŐ ĨŽƌ ƐƵĸĐŝĞŶƚ ƉŽǁĞƌ ƚŽ ŝĚĞŶƟĨǇŶŽǀĞůWƌŝƐŬĨĂĐƚŽƌƐ͘tŝƚŚŵŽƌĞƚŚĂŶϭϬϬŵĞŵďĞƌƐĂŶĚŽǀĞƌϮϱƉƵďůŝĐĂƟŽŶƐ͕ ƚŚĞĐŽŶƐŽƌƟƵŵŚĂƐƉƌŽǀĞŶƚŽďĞŽĨŐƌĞĂƚǀĂůƵĞƚŽƚŚĞWƌĞƐĞĂƌĐŚĐŽŵŵƵŶŝƚǇďǇƚŚĞ ŝĚĞŶƟĮĐĂƟŽŶŽĨďŽƚŚDĞŶĚĞůŝĂŶĂŶĚƌŝƐŬŐĞŶĞƐŝŵƉŽƌƚĂŶƚĨŽƌW͘ dŚĞ /W' ĞǀŽůǀĞĚ ĂůŽŶŐ ǁŝƚŚ ƚŚĞ ƚĞŵƉŽƌĂů ĐŚĂŶŐĞƐ ŝŶ ŐĞŶŽŵŝĐ ƚĞĐŚŶŝƋƵĞƐ͕ ĂĚǀĂŶĐŝŶŐƚŽE'^ƐƚƌĂƚĞŐŝĞƐďǇƐƚĂƌƟŶŐĂt^ƉƌŽũĞĐƚŝŶϮϬϭϬĂŝŵŝŶŐƚŽƐĞƋƵĞŶĐĞϭ͕ϱϬϬ W ƐƵďũĞĐƚƐ͘ dŚĞ ůĂďŽƌĂƚŽƌŝĂů ĂĐƟǀŝƟĞƐ ƚŽ ŐĞŶĞƌĂƚĞ ƚŚĞ t^ ĚĂƚĂƐĞƚ ĐŽǀĞƌĞĚ ϱ ǇĞĂƌƐ͕ ƌĞƐƵůƟŶŐŝŶǀĂƌŝŽƵƐĚĂƚĂĨƌĞĞǌĞƐƚŚĞƌĞďǇĐƌĞĂƟŶŐŵƵůƟƉůĞǀĞƌƐŝŽŶƐŽĨƚŚĞt^ĚĂƚĂƐĞƚ ǁŝƚŚŝŶĐƌĞĂƐŝŶŐŶƵŵďĞƌŽĨƐĂŵƉůĞƐŝǌĞ͘ĞƐŝĚĞƐƚŚĞĐůĂƐƐŝĐĂůƐŝŶŐůĞͲŵĂƌŬĞƌĂƐƐŽĐŝĂƟŽŶƐ͕ ƚŚĞƌĂƌĞǀĂƌŝĂŶƚĂŐŐƌĞŐĂƟŽŶĂŶĂůǇƐŝƐ ǁĂƐƉĞƌĨŽƌŵĞĚĨŽƌĞǀĞƌǇƐŝŶŐůĞŐĞŶĞ͘/ŶĂĚĚŝƟŽŶ ƚŽƚŚĞƐĞƌĞůĂƟǀĞůǇƐƚƌĂŝŐŚƞŽƌǁĂƌĚĂŶĂůǇƐĞƐƉƌŽĐĞĚƵƌĞƐ͕ŵĞŵďĞƌƐŽĨƚŚĞĐŽŶƐŽƌƟƵŵĂƌĞ ŐŝǀĞŶ ƚŚĞ ĨƌĞĞĚŽŵ ƚŽ ĐŽŶĐĞƉƚƵĂůŝǌĞ ŚǇƉŽƚŚĞƐĞƐ ĂŶĚ ƉĞƌĨŽƌŵ ŐĞŶĞƟĐ ĂŶĂůǇƐĞƐ ƚŽ ƚĞƐƚ them.

Scope of the thesis

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involvement of the candidate genes in PD-related phenotypes, such as mitochondrial

ĚǇƐĨƵŶĐƟŽŶĂŶĚɲͲƐǇŶƵĐůĞŝŶƚŽǆŝĐŝƚǇ͕ƉƌŽǀŝĚĞƐďŝŽůŽŐŝĐĂůŝŶƐŝŐŚƚƐƉŽƐƐŝďůǇƐƚƌĞŶŐƚŚĞŶŝŶŐ ƚŚĞƌĞůĂƟŽŶŽĨƐĞǀĞƌĂůĐĂŶĚŝĚĂƚĞŐĞŶĞƐƚŽW͘

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ϭ͘ WƌŝŶŐƐŚĞŝŵ d͕ :ĞƩĞ E͕ &ƌŽůŬŝƐ ͕ ^ƚĞĞǀĞƐ TD. The prevalence of Parkinson’s disease: Ă ƐǇƐƚĞŵĂƟĐ ƌĞǀŝĞǁ ĂŶĚ ŵĞƚĂͲĂŶĂůǇƐŝƐ͘

DŽǀĞŵĞŶƚ ĚŝƐŽƌĚĞƌƐ ͗ ŽĸĐŝĂů ũŽƵƌŶĂů ŽĨ ƚŚĞ DŽǀĞŵĞŶƚ ŝƐŽƌĚĞƌ ^ŽĐŝĞƚǇ ϮϬϭϰ͖

29(13): 1583-90.

Ϯ͘ 'ŝďď tZ͕ >ĞĞƐ :͘ dŚĞ ƌĞůĞǀĂŶĐĞ ŽĨ the Lewy body to the pathogenesis of idiopathic Parkinson’s disease. Journal of

ŶĞƵƌŽůŽŐǇ͕ ŶĞƵƌŽƐƵƌŐĞƌǇ͕ ĂŶĚ ƉƐǇĐŚŝĂƚƌǇ

ϭϵϴϴ͖ϱϭ;ϲͿ͗ϳϰϱͲϱϮ͘

ϯ͘ <ĂůŝĂ >s͕ >ĂŶŐ ͘ WĂƌŬŝŶƐŽŶ͛Ɛ ĚŝƐĞĂƐĞ͘

LancetϮϬϭϱ͖ϯϴϲ;ϵϵϵϲͿ͗ϴϵϲͲϵϭϮ͘

ϰ͘ ƵŶĐĂŶ 't͕ <ŚŽŽ d<͕ zĂƌŶĂůů :͕ Ğƚ Ăů͘ Health-related quality of life in early Parkinson’s disease: the impact of nonmotor symptoms. DŽǀĞŵĞŶƚĚŝƐŽƌĚĞƌƐ

͗ŽĸĐŝĂůũŽƵƌŶĂůŽĨƚŚĞDŽǀĞŵĞŶƚŝƐŽƌĚĞƌ SocietyϮϬϭϰ͖Ϯϵ;ϮͿ͗ϭϵϱͲϮϬϮ͘

ϱ͘ WŽƐƚƵŵĂ Z͕ ĂƌƐůĂŶĚ ͕ ĂƌŽŶĞ W͕ Ğƚ Ăů͘ /ĚĞŶƟĨǇŝŶŐƉƌŽĚƌŽŵĂůWĂƌŬŝŶƐŽŶ͛ƐĚŝƐĞĂƐĞ͗ pre-motor disorders in Parkinson’s disease. DŽǀĞŵĞŶƚ ĚŝƐŽƌĚĞƌƐ ͗ ŽĸĐŝĂů

ũŽƵƌŶĂůŽĨƚŚĞDŽǀĞŵĞŶƚŝƐŽƌĚĞƌ^ŽĐŝĞƚǇ

ϮϬϭϮ͖Ϯϳ;ϱͿ͗ϲϭϳͲϮϲ͘

ϲ͘ <ŚŽŽd<͕zĂƌŶĂůů:͕ƵŶĐĂŶ't͕ĞƚĂů͘dŚĞ spectrum of nonmotor symptoms in early Parkinson disease. NeurologyϮϬϭϯ͖ϴϬ;ϯͿ͗ 276-81.

ϳ͘ dŽůŽƐĂ ͕ 'ĂŝŐ ͕ ^ĂŶƚĂŵĂƌŝĂ :͕ ŽŵƉƚĂ Y. Diagnosis and the premotor phase of Parkinson disease. Neurology ϮϬϬϵ͖ ϳϮ;ϳ Suppl): S12-20.

8. Lang AE. In pursuit of prodromal

Parkinson’s disease. Lancet neurology ϮϬϭϱ͖ϭϰ;ϭͿ͗ϮϳͲϴ͘

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ĂŶĚ ĂŶǆŝĞƚǇ ƐƵďƚǇƉĞƐ ŝŶ ƉĂƟĞŶƚƐ ǁŝƚŚ Parkinson’s disease. DŽǀĞŵĞŶƚĚŝƐŽƌĚĞƌƐ͗ ŽĸĐŝĂůũŽƵƌŶĂůŽĨƚŚĞDŽǀĞŵĞŶƚŝƐŽƌĚĞƌ SocietyϮϬϬϵ͖Ϯϰ;ϵͿ͗ϭϯϯϯͲϴ͘ 19. Wickremaratchi MM, Ben-Shlomo Y, DŽƌƌŝƐ,Z͘dŚĞĞīĞĐƚŽĨŽŶƐĞƚĂŐĞŽŶƚŚĞ clinical features of Parkinson’s disease.

ƵƌŽƉĞĂŶũŽƵƌŶĂůŽĨŶĞƵƌŽůŽŐǇ͗ƚŚĞŽĸĐŝĂů ũŽƵƌŶĂů ŽĨ ƚŚĞ ƵƌŽƉĞĂŶ &ĞĚĞƌĂƟŽŶ ŽĨ EĞƵƌŽůŽŐŝĐĂů^ŽĐŝĞƟĞƐϮϬϬϵ͖ϭϲ;ϰͿ͗ϰϱϬͲϲ͘ ϮϬ͘ ĂůŶĞ ^D͕ <ƵŵĂƌ ͘ zŽƵŶŐ ŽŶƐĞƚ WĂƌŬŝŶƐŽŶ͛ƐĚŝƐĞĂƐĞ͘WƌĂĐƟĐĂůŵĂŶĂŐĞŵĞŶƚ of medical issues. WĂƌŬŝŶƐŽŶŝƐŵΘƌĞůĂƚĞĚ ĚŝƐŽƌĚĞƌƐϮϬϬϴ͖ϭϰ;ϮͿ͗ϭϯϯͲϰϮ͘ Ϯϭ͘ 'ŝďďtZ͕>ĞĞƐ:͘ŶĂƚŽŵǇ͕ƉŝŐŵĞŶƚĂƟŽŶ͕ ǀĞŶƚƌĂů ĂŶĚ ĚŽƌƐĂů ƐƵďƉŽƉƵůĂƟŽŶƐ ŽĨ ƚŚĞ ƐƵďƐƚĂŶƟĂ ŶŝŐƌĂ͕ ĂŶĚ ĚŝīĞƌĞŶƟĂů ĐĞůů death in Parkinson’s disease. Journal of

ŶĞƵƌŽůŽŐǇ͕ ŶĞƵƌŽƐƵƌŐĞƌǇ͕ ĂŶĚ ƉƐǇĐŚŝĂƚƌǇ

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