Kaufman oculocerebrofacial syndrome: case report of a UBE3B splice site variant and clinical overview of reported patients.

Abstract

Background: Kaufman oculocerebrofacial syndrome (KOS; OMIM #244450)is a rare autosomal recessive disorder caused by pathogenic biallelic variants in UBE3B, characterized by craniofacial dysmorphism, global developmental delay, hypotonia, and multisystem anomalies.

Case presentation: We describe a 12-month-old Jordanian girl born to consanguineous parents, who exhibited microcephaly, hypotonia, feeding difficulties, and failure to thrive. Echocardiography revealed a mild basal septal hypertrophy. Developmental evaluation confirmed moderate global delay. Whole-exome sequencing revealed a homozygous UBE3B splice site variant (c.1741 + 2T > C), previously reported as pathogenic in ClinVar and classified as pathogenic according to ACMG/AMP criteria but without a detailed phenotypic description. Family history revealed additional neonatal deaths in a consanguineous context, raising the possibility of an underlying autosomal recessive condition.

Conclusion: This case adds to the limited body of literature on KOS and provides further evidence for the pathogenicity of the c.1741 + 2T > C variant. This case highlights the importance of considering KOS in infants presenting with characteristic craniofacial features such as blepharophimosis, ptosis, preauricular tags, and developmental delay, particularly in consanguineous families.