Genetic Diagnostics and Phenotypic Profiling of a Girl With Autosomal Recessive Intellectual Developmental Disorder and Autism.

In this article, we present a case study of a five-year-old girl with autism and developmental delay, conducted at the Academic Center for Autism Research in Bratislava, Slovakia. The girl was diagnosed using Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) and Autism Diagnostic Interview-Revised (ADI-R) instruments and met the criteria for autism spectrum disorder. Intellectual functioning was in the markedly below-average range, as indicated by the Snijders-Oomen Nonverbal Intelligence Test-Revised (SON-R) examination, and her level of adaptive functioning was significantly reduced. Neurological signs included atypical leukoencephalopathy, hypotonia, sensorineural hearing loss, and sleep disturbances. The patient underwent genetic testing, including microarray-based copy number variation (CNV) detection, which yielded negative results. However, whole exome sequencing (WES) analysis pointed out a damaging homozygous variant in the EIF3F (Eukaryotic Translation Initiation Factor 3 Subunit F) gene, confirming the diagnosis of intellectual developmental disorder autosomal recessive 67. Segregation analysis in the family revealed that the asymptomatic parents were carriers of the pathogenic variant in EIF3F. Our study contributes to the phenotypic profiling of this rare syndromic neurodevelopmental disorder and points out the irreplaceability of WES analysis in genetic diagnostics of autism and developmental delay. This appeals to the need for WES to be accepted as a routine diagnostic tool in Slovakia.