Recurrent human 16p11.2 microdeletions in type I Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome patients in Chinese Han population

Abstract

BackgroundsMayer‐Rokitansky‐Küster‐Hauser (MRKH) syndrome, a severe congenital malformation of the female genital tract, is a highly heterogeneous disease which has no clear etiology. Previous studies have suggested that copy number variations (CNVs) and single‐gene mutations might contribute to the development of MRKH syndrome. In particular, deletions in 16p11.2, which are suggested to be involved in several congenital diseases, have been reported in Chinese type II MRKH patients and European MRKH patients. However, few CNVs including 16p11.2 microdeletions were identified in Chinese type I MRKH cases although it accounted for the majority of MRKH patients in China. Thus, we conducted a retrospective study to identify whether CNVs at human chromosome 16p11.2 are risk factors of type I MRKH syndrome in the Chinese Han population.MethodsWe recruited 143 patients diagnosed with type I MRKH between 2012 and 2014. Five hundred unrelated Chinese without congenital malformation were enrolled in control group, consisting of 197 from the 1000 Genomes Project and 303 from Fudan University. Quantitative PCR, array comparative genomic hybridization, and sanger sequencing were conducted to screen and verify candidate variant.ResultsOur study identified recurrent 16p11.2 microdeletions of approximately 600 kb in two out of the 143 type I MRKH syndrome patients using high‐density array‐based comparative genomic hybridization (aCGH), while no 16p11.2 deletion was found in the control group. We did not find any mutations in TBX6 gene in our samples.ConclusionsThe results of the study identify 16p11.2 deletion in Chinese MRKH I patients for the first time, as well as support the contention that 16p11.2 microdeletions are associated with MRKH syndrome in both types across populations. It is suggested that 16p11.2 microdeletions should be included in molecular diagnosis and genetic counseling of female reproductive tract disorders.

Genetics of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome: advancements and implications

“…In 2011, Nik-Zainal et al (71) reported four cases with recurrent deletions of 16p11.2 and suggested TBX6, previously implicated in paraxial mesoderm development (131), as a candidate gene. To date, a large number of cases have been identified with both deletions (30,(71)(72)(73)(74)(75)(76)(77)(78)(79) and TBX6 sequence variants (72,75,103,105,111,112). The 16p11.2/TBX6 locus is also associated with congenital scoliosis (132).…”