Familial deafness, congenital heart defects, and posterior embryotoxon caused by cysteine substitution in the first epidermal-growth-factor-like domain of jagged 1.
In the present study, we report a kindred with hearing loss, congenital heart defects, and posterior embryotoxon, segregating as autosomal dominant traits. Six of seven available affected patients manifested mild-to-severe combined hearing loss, predominantly affecting middle frequencies. Two patients were diagnosed with vestibular pathology. All patients had congenital heart defects, including tetralogy of Fallot, ventricular septal defect, or isolated peripheral pulmonic stenosis. No individual in this family met diagnostic criteria for any previously described clinical syndrome. A candidate-gene approach was undertaken and culminated in the identification of a novel Jagged 1 (JAG1) missense mutation (C234Y) in the first cysteine of the first epidermal-growth-factor-like repeat domain of the protein. JAG1 is a cell-surface ligand in the Notch signaling pathway. Mutations in JAG1 have been identified in patients with Alagille syndrome. Our findings revealed a unique phenotype with highly penetrant deafness, posterior embryotoxon, and congenital heart defects but with variable expressivity in a large kindred, which demonstrates that mutation in JAG1 can cause hearing loss.
Le Caignec
C
C
Laboratoire d'Etude du Polymorphisme de l'ADN, Faculté de Médecine, Nantes, France. lecaignec@hotmail.com
Lefevre
M
M
Schott
J J
JJ
Chaventre
A
A
Gayet
M
M
Calais
C
C
Moisan
J P
JP
D000015:Abnormalities, Multiple / Q000235:genetics*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001112:Arcus Senilis / Q000151:congenital / Q000235:genetics*; D001483:Base Sequence; D002135:Calcium-Binding Proteins; D003545:Cysteine / Q000737:chemistry; D004247:DNA / Q000235:genetics; D003638:Deafness / Q000151:congenital / Q000235:genetics*; D005260:Female; D005799:Genes, Dominant; D006330:Heart Defects, Congenital / Q000235:genetics*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008297:Male; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D000072099:Serrate-Jagged Proteins
D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D011506:Proteins; D000072099:Serrate-Jagged Proteins; D004247:DNA; D003545:Cysteine