The Process of Diagnosing Xia Gibbs Syndrome in A Male Child with Autism Spectrum Disorder and AHDC1 Gene Mutation: Case Report.

Xia Gibbs Syndrome (XGS) is a rare disorder with different phenotypic and behavioral manifestations and clinical reflections known to develop as a result of de novo mutations in the AT-Hook DNA binding motif (AHDC1). Our patient was first evaluated in the pediatric psychiatry clinic at the age of 2 because of speech delay. The patient was followed up with a diagnosis of cognitive retardation and joint hypermobility was found as a result of pediatric neurology consultation due to his dysmorphic appearance. No pathology was found in detailed blood tests and imaging studies. During the follow-up period, it was determined that the cognitive skills gained between the ages of 4-4.5 started to regress, there was no joint attention, but there was stereotypic movements and limitation in eye contact. In the detailed genetic evaluation performed due to the deterioration in the clinical course and the addition of the diagnosis of Autism Spectrum Disorder, a mutation compatible with Xia Gibbs Syndrome was found in the whole exon sequencing test. Repeated psychiatric and medical evaluation as part of a multidisciplinary approach in rare genetic diseases such as Xia Gibbs Syndrome is important for educational planning and treatment of comorbidities. With this case, we wanted to emphasize the importance of psychiatric follow-up and further investigations especially in cases with loss of acquired skills after diagnosis.