A Homozygous Missense Variant in PPP1R1B/DARPP-32 Is Associated With Generalized Complex Dystonia

© 2021 International Parkinson and Movement Disorder Society..

BACKGROUND: The dystonias are a heterogeneous group of hyperkinetic disorders characterized by sustained or intermittent muscle contractions that cause abnormal movements and/or postures. Although more than 200 causal genes are known, many cases of primary dystonia have no clear genetic cause.

OBJECTIVES: To identify the causal gene in a consanguineous family with three siblings affected by a complex persistent generalized dystonia, generalized epilepsy, and mild intellectual disability.

METHODS: We performed exome sequencing in the parents and two affected siblings and characterized the expression of the identified gene by immunohistochemistry in control human and zebrafish brains.

RESULTS: We identified a novel missense variant (c.142G>A (NM_032192); p.Glu48Lys) in the protein phosphatase 1 regulatory inhibitor subunit 1B gene (PPP1R1B) that was homozygous in all three siblings and heterozygous in the parents. This gene is also known as dopamine and cAMP-regulated neuronal phosphoprotein 32 (DARPP-32) and has been involved in the pathophysiology of abnormal movements. The uncovered variant is absent in public databases and modifies the conserved glutamate 48 localized close to the serine 45 phosphorylation site. The PPP1R1B protein was shown to be expressed in cells and regions involved in movement control, including projection neurons of the caudate-putamen, substantia nigra neuropil, and cerebellar Purkinje cells. The latter cells were also confirmed to be positive for PPP1R1B expression in the zebrafish brain.

CONCLUSIONS: We report the association of a PPP1R1B/DARPP-32 variant with generalized dystonia in man. It might be relevant to include the sequencing of this new gene in the diagnosis of patients with otherwise unexplained movement disorders. © 2021 International Parkinson and Movement Disorder Society.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:37

Enthalten in:

Movement disorders : official journal of the Movement Disorder Society - 37(2022), 2 vom: 24. Feb., Seite 365-374

Sprache:

Englisch

Beteiligte Personen:

Khan, Amjad [VerfasserIn]
Molitor, Anne [VerfasserIn]
Mayeur, Sylvain [VerfasserIn]
Zhang, Gaoqun [VerfasserIn]
Rinaldi, Bruno [VerfasserIn]
Lannes, Béatrice [VerfasserIn]
Lhermitte, Benoît [VerfasserIn]
Umair, Muhammad [VerfasserIn]
Arold, Stefan T [VerfasserIn]
Friant, Sylvie [VerfasserIn]
Rastegar, Sepand [VerfasserIn]
Anheim, Mathieu [VerfasserIn]
Bahram, Seiamak [VerfasserIn]
Carapito, Raphael [VerfasserIn]

Links:

Volltext

Themen:

Autosomal recessive generalized dystonia; exome sequencing; PPP1R1B; DARPP-32
Case Reports
Dopamine and cAMP-Regulated Phosphoprotein 32
Journal Article
PPP1R1B protein, human
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 17.03.2022

Date Revised 31.05.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/mds.28861

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM333580885