Zhao D, Li Y, Shan Z, et al. - In this case report, researchers sought to analyze the function of a compound heterozygous thyroid peroxidase (TPO) mutation in a Chinese family. For this analysis, they reported a case of 23‐year‐old Chinese girl with a history of growth retardation and severe constipation from the age of 3 months, who was diagnosed as having congenital hypothyroidism. Genomic DNA was derived from peripheral blood samples collected from family members of the patient. A compound heterozygous mutation (c.C1993T, c.T2473C) was identified in the TPO gene. A novel compound heterozygous mutation of TPO gene has been identified in a Chinese family. This mutation could alter TPO's extracellular microstructure and reduce its expression and activity, leading to congenital hypothyroidism.