Identification of two novel chromosome regions associated with isolated growth hormone deficiency

The goal of this study was to identify novel candidate genes that may cause or predispose to growth hormone (GH) deficiency. DNA samples from 45 individuals with isolated GH deficiency were assessed using oligonucleotide microarray comparative genomic hybridization. Five individuals with previously unreported copy number variants were identified. Two of the five individuals were hemizygous for regions already known to cause GH deficiency (chromosomes 22q11.21 and 15q26.3). The remaining three individuals had copy number changes involving two novel chromosome regions. One individual had a homozygous deletion of a 2.2 Mb region of 13q33.1 that contains a single gene: integrin, beta-like 1 (ITGBL1). The remaining two individuals had duplications of 4.7 Mb on chromosome 20q13.13. This region includes eight genes not previously identified as copy number variants. These genes are ARFGEF2, CSE1L, DDX27, ZNFX1, C20orf199, SNORD12, KCNB1, and PTGIS. Thus, further investigations into these potential candidate genes are necessary.