Objective: This study aims to investigate the gene mutational characteristics of cathepsin C (CTSC) gene in a Chinese patient with Papillon-Lefèvre syndrome (PLS), then further confirm the genetic basis for the phenotype of PLS, and obtain genetic information that can be used as guide in the diagnosis and treatment of PLS.
Methods: With their consent, peripheral blood samples were obtained from the proband and his family members (his parents and older sister) for genomic DNA extraction. The coding region and exon/intron boundaries of the CTSC gene were amplified and sequenced using poly-merase chain reaction and direct sequencing of DNA.
Results: Compound heterozygous mutations of CTSC gene were iden-tified in the patient. The proband carries one heterozygous nonsense mutation c.754C>T in exon 5 and one heterozygous missense mutation c.1040A>G in exon 7. Both parents were heterozygous carriers without the clinical symptoms of PLS. None of the mutations were detected in the proband's sister.
Conclusions: The study proves that mutations of CTSC gene are responsible for the phenotype of Papillon-Lefèvre syndrome. .
目的 通过研究一例掌跖角化-牙周破坏综合征（PLS）患者及其家系组织蛋白酶C（CTSC）基因突变的特点，提供PLS分子致病机制的理论依据，丰富PLS基因诊断和治疗的科学资料。方法 取得临床发现的一例PLS先证者及其家属知情同意，分别提取先证者及其父母、姐姐的基因组DNA，应用聚合酶链反应和DNA直接测序技术，分析先证者及其直系血亲CTSC基因的突变情况。结果 PLS先证者CTSC基因存在复合型杂合突变，突变位点是c.754C>T和c.1040A>G，其父母均为携带者，姐姐未发现突变。结论 PLS先证者的临床表征是由CTSC基因突变引起。.
Keywords: Papillon-Lefèvre syndrome; cathepsin C; gene mutation.