Genetic characterization and long-term management of severely affected siblings with intellectual developmental disorder with cardiac arrhythmia syndrome.
Mol Genet Metab Rep
; 23: 100582, 2020 Jun.
Article
em En
| MEDLINE
| ID: mdl-32280589
ABSTRACT
We report two brothers with severe global cognitive and motor delay, cortical visual impairment and sick sinus syndrome who were born to consanguineous parents. Standard genetic evaluations did not reveal the cause of their mental retardation. As expected, chromosomal microarray (CMA) revealed extensive regions of homozygosity. Exome sequencing revealed that both affected boys were homozygous for a nonsense mutation in the G-protein ß5 (GNB5) gene (NM_016194.3c.1032C > G; Tyr344Ter), and that the parents were carriers of this mutation. No other DNA variants that were explanatory for the sick sinus or the developmental delay/intellectual disability were identified, and no other clinical parameters are likely to have contributed to this unusual combination of phenotypes. The neurologic features of our patients are more severe than those of most of the other patients previously reported with GNB5 variants, probably because of the homozygous, complete loss-of-function (nonsense/stop-gain) nature of their variant, and their clinical course has been monitored for longer duration.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Mol Genet Metab Rep
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos