Abstract: 【Abstract】 Objective To analyze gene mutations in 3 families with self-improving collodion ichthyosis. Methods Clinical data were collected from 3 patients with self-improving collodion ichthyosis. DNA was extracted from the peripheral blood of patients and their parents, and high-throughput sequencing was performed in the patients by using a multi-gene panel targeting congenital ichthyosis. After identification of causative gene loci, Sanger sequencing was performed to bidirectionally verify the mutations in the patients and their parents. Results All the 3 patients presented with a collodion-like membrane at birth, which was shed within 2 - 4 weeks after birth, and then they gradually showed similar features of mild ichthyosis, including dry skin, tiny scales at local sites, flexural involvement, mild sweating, heat intolerance, cheek flushing, mild palmoplantar keratosis or palmar hyperlinearity. Compound heterozygous mutations were identified in the ALOX12B gene of the 3 patients, including a paternal mutation c.406_408delGAG and a maternal mutation c.77T>C in case 1, a paternal mutation c.1013C>T and a maternal mutation c.1286C>G in case 2, a paternal mutation c.1232T>C and a maternal mutation c.1440C>A in case 3. Function prediction analysis showed that 4 missense mutations c.77T>C, c.1286C>G, c.1013C>T, c.1232T>C and 1 deletion mutation c.406_408delGAG may exert pathogenic effect, and 1 nonsense mutation c.1440C>A led to the generation of a termination codon encoding a truncated protein p.Tyr480Ter, which may affect the protein function and cause disease. None of the 6 mutation sites had been reported in the past. Conclusion Compound heterozygous pathogenic mutations were identified in the ALOX12B gene of the 3 patients with self-improving collodion ichthyosis, which were inherited from their parents.

Key words: Ichthyosis vulgaris, Self-improving collodion ichthyosis, Autosomal recessive congenital ichthyosis, ALOX12B gene, Compound heterozygous mutations