Mosaic 18q21.2 deletions including the TCF4 gene: a clinical report.
Am J Med Genet A
; 158A(12): 3174-81, 2012 Dec.
Article
en En
| MEDLINE
| ID: mdl-23165966
ABSTRACT
Pitt-Hopkins syndrome (PTHS) is characterized by distinctive facial dysmorphism, profound intellectual disability, and the possible occurrence of epilepsy and breathing anomalies. It is caused by haploinsufficiency of the TCF4 gene. No significant difference in clinical severity has been reported to date between PTHS patients carrying 18q21 deletions including the TCF4 gene, and those harboring TCF4 point mutations, suggesting a lack of genotype/phenotype correlation. Moreover, the size of 18q21 deletions including the TCF4 gene does not appear to have a significant effect on the phenotypic severity, suggesting that TCF4 haploinsufficiency is the most important prognostic factor in 18q deletions. We describe two unrelated patients presenting with clinical features reminiscent of PTHS and carrying mosaic interstitial 18q21 deletions characterized by array comparative genomic hybridization. One of the patients presented the lowest level of mosaic 18q21 deletion reported to date (5-10%). Our report and a review of the literature show that the mosaic status does not appear to have a significant effect on the clinical severity of 18q21 deletions, which are associated with a poor neurological outcome, whereas a mosaic TCF4 point mutation can result in a significantly milder phenotype. Malformations of internal organs are currently considered to be rare in PTHS. The patients described here had visceral anomalies, suggesting that a full morphological assessment, including heart and abdominal ultrasound scans, should be performed systematically in PTHS patients.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Cromosomas Humanos Par 18
/
Eliminación de Secuencia
/
Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice
/
Hiperventilación
/
Discapacidad Intelectual
Tipo de estudio:
Prognostic_studies
Límite:
Female
/
Humans
/
Infant
Idioma:
En
Revista:
Am J Med Genet A
Asunto de la revista:
GENETICA MEDICA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Francia