A Microdeletion of Chromosome 9q33.3 Encompasses the Entire LMX1B Gene in a Chinese Family with Nail Patella Syndrome

Abstract

Nail patella syndrome (NPS) is an autosomal dominant disorder characterized by nail malformations, patellar apoplasia, or patellar hypoplasia. Mutations within the LMX1B gene are found in 85% of families with NPS; thus, this gene has been characterized as the causative gene of NPS. In this study, we identified a heterozygous microdeletion of the entire LMX1B gene using multiplex ligation-dependent probe amplification (MLPA) in a Chinese family with NPS. The determination of the deletion breakpoints by Illumina genome-wide DNA analysis beadchip showed that the deletion was located in chromosome 9q33.3 and spanned about 0.66 Mb in size. This heterozygous deletion provides strong evidence for haploinsufficiency as the pathogenic mechanism of NPS.

Genetics of syndromic and non‐syndromic hereditary nail disorders

“…Lunulae anomalies include triangular lunulae or even absent lunulae. So far, no correlation between the range of severity of symptoms and the LMX1B genotype has been reported . MSX1 is another WNT‐associated transcription factor expressed in mesenchyme subjacent to the epithelium of the nail bed that plays roles in the development of teeth and nails.…”