Abstract: Zhao Huijuan, Yan Huimin, Guo Duyi, Zhu Peiqiu, Lei Pengcheng, Lu Xueyan, Jiang Wei Department of Dermatology, Peking University Third Hospital, Beijing 100191, China Corresponding author: Jiang Wei, Email:jiangwei7366@163.com 【Abstract】 Objective To identify a causative gene of autosomal recessive congenital ichthyosis （ARCI） in a Chinese family, and to analyze the genotype?phenotype correlation. Methods Peripheral blood samples were collected from the proband, his elder brother and parents, and genomic DNA was extracted from these blood samples. Genome?wide exome sequencing was conducted to determine the mutation site in the proband, and then allele?specific oligonucleotide primers were designed based on the mutation site. PCR was performed to detect the mutation site to further identify the causative gene of ARCI in the family. Results A new homozygous missense mutation was identified in exon 4 in 1 allele of the PNPLA1 gene in the proband, which led to a codon change from cytosine （C） to thymine （T） at position 700 （c.700C > T） and resulted in the substitution of proline by serine （p.pro234ser）. The same mutation was also detected in the proband′s brother, and his parents were the mutation carriers. No mutations were found in unrelated healthy Chinese individuals. Conclusion The missense mutation in the PNPLA1 gene （p.pro234ser） is associated with clinical symptoms of the patient with ARCI.