Undiagnosed rare disease clinic identifies a novel UBE3A variant in two sisters with Angelman syndrome : The end of a diagnostic odyssey

© 2024 The Authors. Congenital Anomalies published by John Wiley & Sons Australia, Ltd on behalf of Japanese Teratology Society..

Angelman syndrome (AS, MIM #105830) is a neurodevelopmental disorder characterized by severe intellectual disability, profound developmental delay, movement or balance problems, an excessively cheerful disposition, and seizures. AS results from inadequate expression of the maternal UBE3A gene (MIM #601623), which encodes an E3 ligase in the ubiquitin-proteasome pathway. Here we present the case of two sisters with features consistent with AS who had negative methylation analyses. An autism/intellectual disability expanded panel revealed a maternally inherited novel UBE3A (NM_001354506.2) variant c.2443C>T p.(Pro815Ser) in both patients that was initially classified as a variant of uncertain significance. The patients were enrolled in Indiana University's Undiagnosed Rare Disease Clinic (URDC) to further investigate the variant. Additional data, including deep phenotyping, familial segregation analysis, and in silico studies, suggest that the variant is likely pathogenic. 3D modeling studies based on the available crystal structure revealed that the Pro815Ser variant can introduce more flexibility into the protein and alter its enzymatic activity. Recent literature confirms the pathogenic nature of the variant. Reanalysis of the UBE3A variant has heightened existing knowledge of AS and has offered this family an end to their diagnostic odyssey.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - year:2024

Enthalten in:

Congenital anomalies - (2024) vom: 23. März

Sprache:

Englisch

Beteiligte Personen:

Bruns, Rebecca [VerfasserIn]
Liaqat, Khurram [VerfasserIn]
Nasir, Abdul [VerfasserIn]
Treat, Kayla [VerfasserIn]
Murthy, Vinaya S [VerfasserIn]
Mantcheva, Lili [VerfasserIn]
Torres, Wilfredo [VerfasserIn]
Conboy, Erin [VerfasserIn]
Vetrini, Francesco [VerfasserIn]

Links:

Volltext

Themen:

Angelman syndrome
Diagnostic odyssey
Genetic imprinting
Journal Article
Undiagnosed rare disease clinic

Anmerkungen:

Date Revised 23.03.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1111/cga.12566

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370098234