Loss-of-function variants in SRRM2 cause a neurodevelopmental disorder.

PURPOSE: SRRM2 encodes the SRm300 protein, a splicing factor of the SR-related protein family characterized by its serine- and arginine-enriched domains. It promotes interactions between messenger RNA and the spliceosome catalytic machinery. This gene, predicted to be highly intolerant to loss of function (LoF) and very conserved through evolution, has not been previously reported in constitutive human disease. METHODS: Among the 1000 probands studied with developmental delay and intellectual disability in our database, we found 2 patients with de novo LoF variants in SRRM2. Additional families were identified through GeneMatcher. RESULTS: Here, we report on 22 patients with LoF variants in SRRM2 and provide a description of the phenotype. Molecular analysis identified 12 frameshift variants, 8 nonsense variants, and 2 microdeletions of 66 kb and 270 kb. The patients presented with a mild developmental delay, predominant speech delay, autistic or attention-deficit/hyperactivity disorder features, overfriendliness, generalized hypotonia, overweight, and dysmorphic facial features. Intellectual disability was variable and mild when present. CONCLUSION: We established SRRM2 as a gene responsible for a rare neurodevelopmental disease.

Perinatal risk factors for development of retinopathy of prematurity in a tertiary neonatal intensive care unit.

OBJECTIVE: Retinopathy of prematurity (ROP) is a vasoproliferative disorder that is one of the main preventable causes of blindness among preterm neonates. This study aimed to determine the incidence of ROP and investigate the relationship between perinatal risk factors and ROP development. METHODS: This retrospective, non-interventional, non-comparative, hospital-based study was conducted at a tertiary-level neonatal intensive care unit. A total of 163 consecutive patients who met the inclusion criteria were recruited in this study. RESULTS: ROP prevalence was 0.01. During the study period, 44 patients developed ROP (27%), and 119 (73%) did not. Stage I ROP was detected in 8 patients (4.9%); stage II ROP without plus-disease in 26 patients (16%); stage II disease with comorbidities in 1 patient (0.6%); and stage III disease in 9 patients (5.5%). None of the patients showed stage IV and V disease. The mean gestational age was 27.7 ± 2.08 weeks in babies who had ROP and 29.59 ± 1.80 weeks in the other group. Neonates with ROP required more frequent blood transfusion (average, 4.89 ± 3.164 transfusions) compared to their counterparts who received an average of 1.19 ± 1.733 transfusions. Intracranial haemorrhage was identified in 55 (33.7%) patients, of whom 14.1% had ROP. Moreover, neonatal seizures occurred in 23 (14.11%) babies and were more common among babies who had ROP (n = 14). CONCLUSION: This study identified key factors associated with ROP, such as intracranial haemorrhage with or without neonatal seizures and a high frequency of blood transfusions.