OP-123 Nono- associated X- linked intellectual disability syndrome

Aim Introduction: NONO is a TORC-interacting protein that is necessary for cAMP-dependent activation of CREB target genes in vivo. This protein is located on chromosome Xq13.1 and encodes RNA-binding and DNA -binding proteins that involved in RNA synthesis. Hemizygous loss of function NONO variants have been associated with syndromic intellectual disability with left ventricular noncompaction(LVNC), congenital cardiac defects and cardiomyopathy. X-linked recessive syndromic intellectual developmental disorder-34(MRXS34) is characterized by delayed psychomotor development, intellectual disability with poor speech, dysmorphic facial feature, thickening of corpus callosum. Material and Method we reviewed 9 cases related to NONO-associated X-linked intellectual disability syndrome Results A 11 year old male child admitted in our hospital with no signs of life. Child was revived after resuscitation. Child had developmental delay, intellectual disability, dysmorphic facial features, microcephaly, slender build. Facial feature include long face with up slanting palpebral fissures, malar hypoplasia, small open mouth. ECHO showed severe systolic and diastolic function with ejection fraction of 20–25 %. Child exhibited low muscle tone, Neurologic examination showed hypotonia, increased patellar and Achilles reflexes without clonus. CT scan of Brain was normal. Whole exome sequencing showed a hemizygous pathogenic variant in c.1093>t(p.Arg365Ter) variant in NONO gene. A heterozygous variant of uncertain significance in 935G>A ( p.Gly312Glu) variant in TNNI3K gene was also observed in this child. Conclusions We conclude that It is a rare disease with features of developmental delay, cardiomyopathy, dysmorphic facial features. Microcephaly was found in this case as compared to previous 9 cases where macrocephaly was observed. KEYWORDS syndromic intellectual disability, microcephaly, left ventricular noncompaction, NONO gene, TNNI3K gene,