关键词: Kenny-Caffey综合征2型；　FAM111A基因；　甲状旁腺功能减退；　低钙血症

Abstract: Objective　To analyze the clinical features, gene mutations and treatment of rare Kenny-Caffey syndrome type 2. Methods　Clinical and laboratory data and gene detection results from a child with Kenny-Caffey syndrome type 2 were retrospectively analyzed. The related literatures were reviewed. Results　The 8-month old boy presented with recurrent seizures and developmental delay. Laboratory tests suggested hypocalcemia, hypomagnesemia, hyperphosphatemia, low parathyroid hormone and increased liver enzymes. X-ray examination showed long bones with reduced medullary space and cortical thickening. Whole exome sequencing identified a de novo heterozygous mutation of c.1706G>A, p.Arg569His in FAM111A gene. A total of 17 cases of Kenny-Caffey syndrome caused by FAM111A gene mutation were reported in the literature searched, the clinical features are consistent with our patient. Conclusions　Kenny-Caffey syndrome type 2 caused by FAM111A gene mutation is very rare, and genetic testing is helpful for the molecular diagnosis.

Key words: 　Kenny-Caffey syndrome type 2;　FAM111A gene;　hypoparathyroidism;　hypocalcemia