Prenatal diagnosis and molecular cytogenetic analyses of a paternal inherited deletion of 1q23.3 encompassing PBX1 gene

Abstract

Abstract Background Patients with deletions involving the long arm of chromosome 1 are rare. The PBX1 gene is located on chromosome 1q23.3. PBX1 encodes a transcription factor which promotes protein–protein interaction and plays a crucial role in several developmental processes. PBX1 haploinsufficiency had been reported to lead syndromic congenital anomalies of kidney and urinary tract (CAKUT) in humans. Case presentation In this research, a 24-year-old woman (gravida 1, para 0) underwent amniocentesis at 22 weeks’ gestation because of a horseshoe kidney of the fetus on prenatal ultrasound. Results Chromosomal microarray analysis (CMA) from this family revealed a 1.14 Mb paternal inherited deletion on chromosome 1q23.3, spanning from position 163,620,000 to 164,760,000 (hg19). Trio whole-exome sequencing (WES) showed heterozygous deletions in exons 1–2 of the PBX1 in fetal and paternal samples. At the 3-year follow-up, the baby did not have an abnormal phenotype except a horseshoe kidney. Conclusion We provide a detailed description of the phenotype in a family with paternal inherited deletion of 1q23.3 encompassing exons 1–2 of the PBX1 gene. Combination of karyotype analysis, CMA, WES, prenatal ultrasound and genetic counseling is helpful for the prenatal diagnosis of chromosomal microdeletions/microduplications.

Keywords

• PBX1
• Chromosomal microdeletions/microduplications
• Chromosomal microarray analysis
• Congenital anomalies of kidney and urinary tract
• Ultrasound
• Prenatal diagnosis