Purpose:
1p36 deletion syndrome is the most common terminal deletion syndrome, with an incidence of 1/5,000 newborns. But 22q13 duplications seem to be exceedingly rare. A combined 1p36 deletion and 22q13 duplication was more rarely observed and presented variability of clinical features, which increases the importance of reporting additional cases in order to better characterize genotype-phenotype correlations.
Methods:
A boy and a fetus from a single family with combined 1p36 deletion and 22q13 duplication characterized by array CGH and MLPA were described here.
Results:
The proband presented severe developmental delay, hypotonia, epilepsy, feeding difficulties with failure to thrive, tracheal malformation, clinodactyly, strephexopodia, fair skin, facial dysmorphism and died at 1 year of age. Array CGH uncovered a 9.3-Mb deletion of 1p36 plus a 6.655-Mb duplication of 22q13in the proband. This rearrangement was confirmed by MLPA. When his mother was pregnant again, array CGH detected an almost identical rearrangement with that of the proband. She terminated the pregnancy at 24 weeks gestation. The fetus was female and had similar facial dysmorphism as the proband. Karyotypes of parents are all normal.
Conclusions:
Most of the features in the proband were similar to those associated with both isolated 1p36 deletions and 22q13 duplications. However, tracheal malformation, fair skin and strephexopodia were only observed in our patient. Given that 22q13 duplications are rare and not as well characterized as 1p36 deletions, we attributed these features to 22q13 duplications. Importantly, we emphasize importance of prenatal diagnosis of females who had such abnormal pregnancy.