A novel Xq22.1 deletion in a male with multiple congenital abnormalities and respiratory failure

Here we report the first male case of a novel Xq22.1 deletion. An 8-week-old boy with multiple congenital abnormalities and respiratory failure was referred to the Mayo Clinic Cytogenetics laboratory for testing. Chromosomal microarray analysis identified a novel 1.1 Mb deletion at Xq22.1. A similar deletion has only been described once in the literature in a female patient and her mother; both have intellectual disability and dysmorphic facial features. In addition, the mother had a son who died at 15 days due to breathing failure. Recently, a mouse model revealed that a 0.35 Mb sub-region, containing 4 genes, is sufficient to cause majority of the Xq22.1 deletion phenotypes. The deleted intervals in our male patient and the female patients contain 15 common genes, including the four described in the 0.35 Mb sub-region. Male mice with deletion of the 0.35 Mb sub-region died perinatally from respiratory failure due to pulmonary hypoplasia, consistent with the breathing problem and potential neonatal fatality in male patients. The phenotypes of the mouse models and the patients are strikingly similar; therefore, the deletion of these five genes (ARMCX5, ARMCX5-GPRASP2, GPRASP1, GPRASP2, and BHLHB9) is likely responsible for the novel Xq22.1 deletion syndrome.