Subtelomeric deletions of chromosome 6p: molecular and cytogenetic characterization of three new cases with phenotypic overlap with Ritscher-Schinzel (3C) syndrome.

We have identified six children in three families with subtelomeric deletions of 6p25 and a recognizable phenotype consisting of ptosis, posterior embryotoxon, optic nerve abnormalities, mild glaucoma, Dandy-Walker malformation, hydrocephalus, atrial septal defect, patent ductus arteriosus, and mild mental retardation. There is considerable clinical overlap between these children and individuals with the Ritscher-Schinzel (or cranio-cerebello-cardiac (3C)) syndrome (OMIM #220210). Clinical features of 3C syndrome include craniofacial anomalies (macrocephaly, prominent forehead and occiput, foramina parietalia, hypertelorism, down-slanting palpebral fissures, ocular colobomas, depressed nasal bridge, narrow or cleft palate, and low-set ears), cerebellar malformations (variable manifestations of a Dandy-Walker malformation with moderate mental retardation), and cardiac defects (primarily septal defects).

Coloboma and other ophthalmologic anomalies in Kabuki syndrome: distinction from charge association.

Kabuki (Niikawa-Kuroki) syndrome is associated with growth retardation, developmental delay, congenital heart disease, cleft palate, and characteristic facial features. Although the external appearance of the eyes has been well-described, the type and frequency of structural and functional eye anomalies has not been emphasized. We report three children with Kabuki syndrome who also had a retinal coloboma.

Analysis of cardiovascular phenotype and genotype-phenotype correlation in individuals with a JAG1 mutation and/or Alagille syndrome.

Background: Cardiovascular anomalies are among the most common features of Alagille syndrome (AGS). Mutations of JAG1 are found in most individuals with AGS. This study was undertaken to determine the spectrum of cardiovascular phenotypes associated with a JAG1 mutation and/or AGS, investigate potential genotype-phenotype correlations, and begin to correlate clinical outcome with genetic pathogenesis.

Alagille syndrome inherited from a phenotypically normal mother with a mosaic 20p microdeletion.

We report an 18-month-old girl with Alagille syndrome, caused by a submicroscopic deletion of chromosome 20p, including the Jagged1 (JAG1) gene. FISH using a BAC probe containing JAG1 identified the deletion. Chromosomes were normal at the 550 band level.

Craniosynostosis in Alagille syndrome.

Alagille syndrome is a multisystem developmental disorder with primary involvement of the liver, heart, skeleton, eyes and facial structures, and demonstrates highly variable expressivity with respect to all of the involved systems. Alagille syndrome is caused by mutations in the Jagged1 gene. Jagged1 is a ligand in the Notch signaling pathway that has been shown to regulate early cell fate determination.