A de novo microdeletion 2p24.3-25.1 identified in a girl with global development delay

H Ivanov ,Aleksandar Linev,Radoslava Vazharova,Vili K Stoyanova,Samuil Ivanov,Lubomir Balabanski,Иван Иванов ,Драга Тончева

doi:10.7750/biodiscovery.2015.18.1

Abstract

Interstitial microdeletions of the distal 2p are very rare. A small number of cases have been reported in the literature, involving regions 2p23-p25, 2p23-p24 and 2p24-p25. The most common symptoms involve: intrauterine growth retardation, developmental delay, mental retardation, microcephaly, craniofacial anomalies, musculoskeletal abnormalities, congenital heart defect and hearing impairment. Herein we report on a Caucasian girl, born after in vitro fertilization with discrete facial dysmorphism, growth failure, borderline neurodevelopment and congenital heart defect. A de novo pericentric inversion of chromosome 2 was identified by routine karyotyping. An interstitial microdeletion of 2p24.3p25.1 was found by array karyotyping and following FISH analysis revealed that the deletion affects the inverted chromosome 2. This case illustrates the utility of high resolution methods to identify submicroscopic quantitative changes in structurally rearranged chromosomes. The precise determination of the genetic content of small quantitative changes in the genome provides important information for genetic counseling, enabling to predict the course of disease and the planning of adequate therapy and prophylaxis in affected families.

Highlights

Constitutional interstitial deletions of the distal short arm of chromosome 2 are very rare
We report on a girl with discrete facial dysmorphism, global development delay and congenital heart defect
A de novo pericentric inversion of chromosome 2 was found by routine karyotyping and an interstitial microdeletion 2p24.3-p25.1 was identified by array karyotyping

Summary

Introduction

Constitutional interstitial deletions of the distal short arm of chromosome 2 are very rare. Clinical Report The proband is a Caucasian girl who came to our genetic clinic because of dysmorphism, growth failure and suspected neurodevelopmental delay She was born at 37th gestational week of a twin pregnancy after in vitro. Initial physical examination demonstrated axial musclе hypotonia.At the time of examination the proband is 1 year and 5 months old Her weight is 6 kg (-3.23 SD), height is 64 cm (-3.9SD) and her head circumference is 39 cm (-4.38 SD). Dysmorphic features include: hypertelorism, epicanthus, hirsutism of the forehead, prominent metopic suture, depressed nasal bridge, down slanting mouth corners, low set large and simple ears, high arched palate, misaligned dentition, carious teeth, short neck and low hairline at the neck. The analysis revealed a heterozygous interstitial microdeletion encompassing 4.46 Mb in the short arm of chromosome 2 with breakpoints in bands 2p24.3 and 2p25.1 – arr[hg19] 2p2 5.1p24.3(8,822,787-13,462,596)x1 (Fig. 3). In all analyzed metaphases it was obvious that the deletion affects the inverted chromosome 2 (Fig. 4)

Discussion

Conclusion