Pure 16q21q22.1 deletion in a complex rearrangement possibly caused by a chromothripsis event.

Rita Genesio,Angela Mormile,Pia Castelluccio,Lucio Nitsch,Graziella Leone,Valentina Ronga,Maria Luigia Cavaliere,Anna Conti,Gennaro Fioretti

doi:10.1186/1755-8166-6-29

Rita Genesio, Angela Mormile + Show 7 more

Open Access

https://doi.org/10.1186/1755-8166-6-29

Copy DOI

Abstract

BackgroundPartial monosomies of chromosome 16q are rare and overlapping effects from complex chromosomal rearrangements often hamper genotype-phenotype correlations for such imbalances. Here, we report the clinical features of an isolated partial monosomy 16q21q22.1 in a boy with a complex de novo rearrangement possibly resulting from a chromothripsis event.ResultsThe patient presented with low birth weight, microcephaly, developmental delay, facial dysmorphisms, short stature, dysmorphic ears and cardiopathy. Standard and molecular cytogenetics showed a complex rearrangement characterised by a pericentromeric inversion in one of chromosomes 12 and an inverted insertional translocation of the 12q14q21.1 region, from the rearranged chromosome 12, into the q21q22.1 tract of a chromosome 16. Array-CGH analysis unravelled a partial 16q21q22.1 monosomy, localised in the rearranged chromosome 16.ConclusionsThe comparison of the present case to other 16q21q22 monosomies contributed to narrow down the critical region for cardiac anomalies in the 16q22 deletion syndrome. However, more cases, well characterised both for phenotypic signs and genomic details, are needed to further restrict candidate regions for phenotypic signs in 16q deletions. The present case also provided evidence that a very complex rearrangement, possibly caused by a chromothripsis event, might be hidden behind a classical phenotype that is specific for a syndrome.

Highlights

Partial monosomies of chromosome 16q are rare and overlapping effects from complex chromosomal rearrangements often hamper genotype-phenotype correlations for such imbalances
In spite of some specific phenotypes associated with the extension and localisation of the deleted regions, a critical region for this deletion syndrome is not clearly defined, as both 16q12.1q13 and 16q22 deletions are associated with similar phenotypic signs [8]
Dual-colour-FISH using either the two Whole Chromosome Painting (WCP) probes for chromosomes 12 and 16 (Figure 3a) or the Bacterial Artificial Chromosome (BAC) probe RP11-485K18 (12p11.2) and Chromosome Enumeration Probes (CEP) 12 (Figure 3b) revealed that the additional material present on the q arm of chromosome 16 was derived from chromosome 12 and confirmed the inversion

Summary

Introduction

Partial monosomies of chromosome 16q are rare and overlapping effects from complex chromosomal rearrangements often hamper genotype-phenotype correlations for such imbalances. We report the clinical features of an isolated partial monosomy 16q21q22.1 in a boy with a complex de novo rearrangement possibly resulting from a chromothripsis event. We present a case of 16q21q22.1 isolated deletion resulting from a complex chromosomal rearrangement. Clinical report The patient is the second child of healthy parents. He was born preterm at 33.6 weeks of gestation with a weight of 2.17 kg, a head circumference of 29.5 cm and length of 45.5 cm (appropriate for gestational age)

Methods

Results

Discussion

Conclusion