CPT® Code 81471

X-linked intellectual disability (XLID) (eg, syndromic and non-syndromic XLID); duplication/deletion gene analysis, must include analysis of at least 60 genes, including ARX, ATRX, CDKL5, FGD1, FMR1, HUWE1, IL1RAPL, KDM5C, L1CAM, MECP2, MED12, MID1, OCRL, RPS6KA3, and SLC16A2

Molecular genetic testing is a critical procedure utilized for diagnosing suspected syndromic or non-syndromic X-linked intellectual disability (XLID). This testing involves a genomic sequence analysis panel that must encompass at least 60 specific genes, which are essential for identifying potential genetic causes of intellectual disability in affected individuals. XLID is characterized by cognitive impairment that is non-progressive and typically manifests before the age of 18. The condition is defined by an intelligence quotient (IQ) of 70 or below, accompanied by impairments in adaptive functioning across at least two domains, such as communication, social skills, self-direction, and the ability to manage health and safety. In most instances, XLID presents as non-syndromic, meaning that there are no additional physical features or symptoms that assist in the diagnosis. Males diagnosed with XLID may exhibit moderate to severe intellectual disability, while carrier females may experience milder symptoms. The testing process involves analyzing whole blood or isolated DNA to assess the presence of mutations in the specified genes, including ARX, ATRX, CDKL5, FGD1, FMR1, HUWE1, IL1RAPL, KDM5C, L1CAM, MECP2, MED12, MID1, OCRL, RPS6KA3, and SLC16A2, using advanced techniques such as massively parallel sequencing. Additionally, to identify deletion or duplication mutations, DNA extracted from whole blood is hybridized to a gene-targeted comparative genomic hybridization (CGH) array. This comprehensive approach ensures accurate detection of genetic anomalies associated with XLID, facilitating appropriate diagnosis and management of affected individuals.