The investigation of chromosomal abnormalities via chromosomal microarray in non-syndromic hirschsprung cases

AIM: Hirschsprung disease is a complex, multifactorial and heterogenus genetic disease which characterised by absence of enteric neuronal ganglion cells and effects different length of distal gastrointestinal system. Besides multigenic hereditary causes some uncertain enviromental factors have also been held on the etiology. On the genetic etiology chromosomal causes (suc as Down syndrome, 10q11 deletion, 17q21 deletion and duplication syndrome), syndromic monogenic causes (Mowat-Wilson syndrome, Waardenburg-Shah syndrome) and non syndromic monogenic causes (RET, EDNRB, PHOX2B) are responsible. The etiology of some cases has not been identified yet. In this study we aim to evaluate the chromosomal abnormalities of HSCR cases which have multiple congenital anomaly but do not fit to known monogenic syndromic causes and determine HSCR related new locuses. MATERIAL and METHOD: Patients are collected from Inonu University Medical Faculty which have been treated and/or followed and consulted to Medical Genetics Outpatient Clinic between 2013-2017 because of multiple congenital anomalies. 13 patients' files and microarray results have been evaluated retrospectively which Affymetrix CytoScan Optima assay were performed. Patients' files, physical examinations, photos, radiological and laboratory findings were evaluated in the light of related departments. The results have been compared with literature that primarily PubMed and other scientific- academic resources. RESULTS: In a girl patient deletion of 2q22 and in a boy patient duplication of 17p12 and in an another boy duplication of Xq12 have been established. Neither microscobic nor submicroscobic chromosomal abnormalities have been identified in ten cases. CONCLUSION: The detection of etiology is important for management of diagnosis, treatment, following and genetic counseling. In this study we have identified new chromosomal rearrangments (and possible locuses) which have not been related with HSCR once. We have detected that genetic counseling can not been effective. We have planned diagnostic tests for undiagnostic patients. Additionally we have prepared algorithms for medical doctors to management of HSCR cases.