Interstitial 1q21.1 Microdeletion Is Associated with Severe Skeletal Anomalies, Dysmorphic Face and Moderate Intellectual Disability.

We report on a Brazilian patient with a 1.7-Mb interstitial microdeletion in chromosome 1q21.1. The phenotypic characteristics include microcephaly, a peculiar facial gestalt, cleft lip/palate, and multiple skeletal anomalies represented by malformed phalanges, scoliosis, abnormal modeling of vertebral bodies, hip dislocation, abnormal acetabula, feet anomalies, and delayed neuropsychological development. Deletions reported in this region are clinically heterogeneous, ranging from subtle phenotypic manifestations to severe congenital heart defects and/or neurodevelopmental findings. A few genes within the deleted region are associated with congenital anomalies, mainly the RBM8A, DUF1220, and HYDIN2 paralogs. Our patient presents with a spectrum of unusual malformations of 1q21.1 deletion syndrome not reported up to date.

Cleft lip/palate, short stature, and developmental delay in a boy with a 5.6-mb interstitial deletion involving 10p15.3p14.

The chromosome interval 10p15.3p14 harbors about a dozen genes. This region has been implicated in a few well-known human phenotypes, namely HDR syndrome (hypoparathyroidism, sensorineural deafness, and renal dysplasia) and DGS2 (DiGeorge syndrome 2), but a number of variable phenotypes have also been reported. Cleft lip/palate seems to be a very unusual finding within the clinical spectrum of patients with this deletion. Here, we report a male child born with short stature, cleft lip/palate, and feeding problems who was found to have a 5.6-Mb deletion at 10p15.3p14.

Detection of classical 17p11.2 deletions, an atypical deletion and RAI1 alterations in patients with features suggestive of Smith-Magenis syndrome.

Smith-Magenis syndrome (SMS) is a complex disorder whose clinical features include mild to severe intellectual disability with speech delay, growth failure, brachycephaly, flat midface, short broad hands, and behavioral problems. SMS is typically caused by a large deletion on 17p11.2 that encompasses multiple genes including the retinoic acid induced 1, RAI1, gene or a mutation in the RAI1 gene. Here we have evaluated 30 patients with suspected SMS and identified SMS-associated classical 17p11.2 deletions in six patients, an atypical deletion of ~139 kb that partially deletes the RAI1 gene in one patient, and RAI1 gene nonsynonymous alterations of unknown significance in two unrelated patients. The RAI1 mutant proteins showed no significant alterations in molecular weight, subcellular localization and transcriptional activity. Clinical features of patients with or without 17p11.2 deletions and mutations involving the RAI1 gene were compared to identify phenotypes that may be useful in diagnosing patients with SMS.