Doctors of the Institute of Clinical Genetics at the Klinikum Stuttgart succeeded in revealing the molecular cause of the to-date unclear syndromic disease of a six year old boy by using CeGaT’s diagnostic sequencing service.
After performing some conventional diagnostics (karyotyping, arrayCGH diagnostics) at the Klinikum Stuttgart, a trio exome analysis (where both patient and parents are examined) from leukocytes revealed a PTPN11 germline mutation that could not completely explain the phenotype. Only with the implementation of CeGaT’s somatic tumor panel was somatic mosaicism of the PIK3CA gene could be detected from a saliva sample of the patient, which confirmed the clinical diagnosis of a megalencephaly-capillary malformation syndrome.
The results were published in the European Journal of Human Genetics. The article explains the coincidence of these two variants; moreover, a novel pathogenetic “second hit” model is presented.