Deletions and duplications of developmental pathway genes in 5q31 contribute to abnormal phenotypes

• Published in: American journal of medical genetics. Part A Vol. 155A; no. 8; pp. 1906 - 1916
• Main Authors: Rosenfeld, Jill A., Drautz, Joanne Milisa, Clericuzio, Carol L., Cushing, Tom, Raskin, Salmo, Martin, Judith, Tervo, Raymond C., Pitarque, Jose A., Nowak, Dorota M., Karolak, Justyna A., Lamb, Allen N., Schultz, Roger A., Ballif, Blake C., Bejjani, Bassem A., Gajecka, Marzena, Shaffer, Lisa G.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.08.2011; Wiley-Liss
• Subjects: 5q31; Abnormalities, Multiple - genetics; aCGH; Biological and medical sciences; Child; Child, Preschool; Chromosome Disorders - diagnosis; Chromosome Disorders - genetics; Chromosomes, Human, Pair 5 - genetics; Classical genetics, quantitative genetics, hybrids; Comparative Genomic Hybridization; corneal abnormality; deletion; Developmental Disabilities - genetics; Diseases of cornea, anterior segment and sclera; duplication; Female; Fundamental and applied biological sciences. Psychology; Gene Deletion; Gene Dosage; Gene Duplication; Genes, Developmental; Genetic Linkage; Genetics of eukaryotes. Biological and molecular evolution; Genome-Wide Association Study; Human; Humans; Infant, Newborn; keratoconus; Keratoconus - genetics; Male; Medical genetics; Medical sciences; Ophthalmology; Phenotype; Sequence Analysis, DNA; Chromosomal aberration; Genetic mapping; Cornea; corneal abnormality; 5q31; Keratopathy; aCGH; duplication; Eye disease; Phenotype; Gene; Keratoconus; Deletion; Abnormal chromosome; Genetics; Chromosome duplication; Anterior segment disease
• ISSN: 1552-4825; 1552-4833; 1552-4833
• DOI: 10.1002/ajmg.a.34100

Although copy number changes of 5q31 have been rarely reported, deletions have been associated with some common characteristics, such as short stature, failure to thrive, developmental delay (DD)/intellectual disability (ID), club feet, dislocated hips, and dysmorphic features. We report on three individuals with deletions and two individuals with duplications at 5q31, ranging from 3.6 Mb to 8.1 Mb and 830 kb to 3.4 Mb in size, respectively. All five copy number changes are apparently de novo and involve several genes that are important in developmental pathways, including PITX1, SMAD5, and WNT8A. The individuals with deletions have characteristic features including DD, short stature, club feet, cleft or high palate, dysmorphic features, and skeletal anomalies. Haploinsufficiency of PITX1, a transcription factor important for limb development, is likely the cause for the club feet, skeletal anomalies, and cleft/high palate, while additional genes, including SMAD5 and WNT8A, may also contribute to additional phenotypic features. Two patients with deletions also presented with corneal anomalies. To identify a causative gene for the corneal anomalies, we sequenced candidate genes in a family with apparent autosomal dominant keratoconus with suggestive linkage to 5q31, but no mutations in candidate genes were found. The duplications are smaller than the deletions, and the patients with duplications have nonspecific features. Although development is likely affected by increased dosage of the genes in the region, the developmental disruption appears less severe than that seen with deletion. © 2011 Wiley‐Liss, Inc.