ABSTRACT
@#Objective Genetic analysis was performed on a female child with chromosome Xq28 heterozygous deletion and suspected X-linked recessive disease to determine the morbidity and prognosis. Methods A female child was admitted to the hospital on day 20 because of "jaundice for 20 days and difficulty in stopping bleeding at acupuncture sites". Low depth whole genome test of amniocentesis in late pregnancy suggested missing copy number of hemophilia A and X-linked mental retardation type 72. In order to further confirm the diagnosis and prognosis, peripheral blood of the children and their parents were collected for gene testing, chromosome inactivation test and genetic analysis. Results Chromosome Xq28 of the child had 439.4 kb copy number heterozygous deletion variation, which was a clear disease-coding gene for functional loss included in ClinGen database. Chromosome inactivation test showed that the paternal X chromosome of the child was extremely inactivated. Haplotype analysis suggested that the normal chromosome of the subject was inherited from the mother, and there was heterozygous deletion on the paternal X chromosome, so it was inferred that the child will not develop disease or just have mild symptoms. Conclusion It is necessary to analyze the X chromosome inactivation test for female patients with the pathogenic variation of X-linked recessive genetic disease to determine the possibility of the disease.