[Clinical and genetic analysis of a child with ZTTK syndrome due to heterozygous variant of SON gene].

ABSTRACT

OBJECTIVE: To explore the genetic etiology of a small-for-date infant with gastrointestinal bleeding, developmental delay and thrombocytopenia (Zhu-Tokita-Takenouchi-Kim syndrome). METHODS: Clinical and laboratory examinations were carried out for the patient. Next-generation sequencing (NGS) was used to detect potential variant associated with the disease. Candidate variant was verified by Sanger sequencing of the child and her parents. RESULTS: NGS revealed that the child has carried a heterozygous c.5751_5754del variant of the SON gene, which resulted in a frameshift p.V1918Efs*87. The same variant was detected in neither parent. CONCLUSION: The heterozygous variant of SON gene probably underlay the ZTTK syndrome in this child. Above finding has enriched the mutational spectrum of the SON gene and provides a basis for genetic counseling and clinical decision-making.