Family of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis caused by a novel FAM111B mutation.

Hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP) is a recently identified autosomal dominant genetic syndrome with mutations in FAM111B. Herein, we report a 14-month-old girl who presented with progressive poikiloderma on the face. Her 24-year-old mother had an identical facial poikiloderma, hyperpigmentation, mottling and Blaschko line hypopigmentation on the trunk and limbs, as well as severe tendon contractures. Next-generation sequencing based on a targeted gene capture panel revealed a missense mutation in the FAM111B gene p.Phe416Ser (c.1247T>C). Her mother had the same mutation as the proband. Moreover, this mutation was absent in the unaffected father and maternal grandparents. Based on the clinical manifestations and genetic analysis, the proband and her mother were diagnosed with POIKTMP. Protein modeling indicated that the mutation p.Phe416Ser dramatically changed the protein structure, especially its structural stability, and affected the protein function. This is the first report of POIKTMP in a Chinese family due to a novel FAM111B mutation. Furthermore, we have reviewed the genotype-phenotype correlation, differential diagnoses and management of POIKTMP.