1q44 microdeletion syndrome: A new case with potential additional features

Abstract

1q44 microdeletion syndrome (1q44 monosomy) is a newly described genetic syndrome characterized by the haploinsufficiency of a 6 Mb locus on the long arm of chromosome 1. The main features are global developmental delay, seizures, hypotonia and craniofacial dysmorphism. With a prevalence below one in a million cases, this syndrome is very rare and, hence, often passes undiagnosed. We present the case of a one year old girl admitted to our hospital with global developmental delay and several congenital abnormalities suggesting a plurimalformative syndrome. Microarray analysis detected a 967 kb deletion in the 1q44 region as well as a a 530 kb microduplication in the 14q31.1q31.2 region, the latter having unknown clinical significance as it contains no currently known OMIM genes. The patient’s phenotype was in accordance to 1q44 microdeletion syndrome. Furthermore, after studying the 1q44 microdeletion syndrome cases reported so far in the literature, we have noticed that our patient presented previously undescribed features of this syndrome, namely prenatal hydronephrosis, bifid hallux and grey matter heterotopy. Based on the cerebral, renal and skeletal involvement in 1q44 microdeletion syndrome, we suspect these might be additional, previously unreported features of 1q44 microdeletion syndrome.