De novo 7q11.21 duplication with 4-hydroxy phenylacetic aciduria– A rare neurodevelopmental syndrome: A Case report

AbstractIntroduction The rearrangement of chromosomal genes, particularly duplication and deletion, is mostly known as a chromosomal disorder. Chromosome 7 has approximately 1.5 million base pairs (Mb); chromosome 7q11.21 region is prone to chromosomal rearrangement. Duplication in any of these regions can cause autism spectrum disorder. Organic acid disorder is when the body's metabolism does not function properly, producing insufficient energy and accumulating harmful substances in the blood and urine. 4-hydroxy phenylacetic acid is a metabolite of the methyl hydrogens substitution, which causes Schizophrenia, ulcerative colitis, and epilepsy. Method We performed Chromosomal microarray analysis (CMA) for the detection of chromosomal duplication from GC lab South Korea on peripheral blood samples and Liquid chromatography-tandem mass spectrometry (LS-MS/MS) for organic acid disorder on urine sample in our patient from Kyungpook National University Chilgok Hospital (Daegu, South Korea). We have reviewed both disorders' clinical features and genotype-phenotype characteristics. Psychological and behavioral modification, dietary modification, and supplementation are being applied appropriately. Result We have identified our patient with 4-hydroxyphenyl acetic aciduria by Liquid chromatography-tandem mass spectrometry (LS-MS/MS), and its concentration was found 84.4 (mmol/mol Cr) and duplication in chromosome 7q11.21 by CMA, which is 444 kb in size likely benign. Discussion We have found various autistic features related to chromosome 7q11.21 duplication and 4-hydroxyphenyl acetic aciduria. Timely treatment, proper diet, special behavioral care, and close monitoring may help improve the patient's condition.