Jiangxi discovered the world’s first human rare abnormal chromosome.

Jiangxi Province Maternal and Child Health Hospital recently discovered a rare human abnormal karyotype from a 3-year-old boy: 46, XY, dup (4) (p12p16). According to Li Yuzhong, the chief technician of the hospital's prenatal diagnosis center, this abnormal chromosome has been identified by the State Key Laboratory of Chinese Medical Genetics and is the world's first discovery.

Li Yuzhong's analysis suggests that this chromosome may be generated at the time of deceleration and division, and non-equivalence exchange between homologous chromosomes or non-equivalence exchange between chromatids to form repeated fragments. According to the degree of pathogenicity of the gene, patients may have congenital non-progressive mental retardation, growth retardation, and accompanied by multiple malformations in facial features, limbs, striae, and internal organs.

According to reports, this karyotype has now been entered into the Chinese Human Chromosome Anomalous Karyotype Database and will help to find out the cause of patients with similar symptoms.