Abstract: Objective To explore the clinical characteristics of Crisponi syndrome (CS) caused by a novel compound heterozygous variation in CRLF1 gene. Methods The clinical data of CS in one child was analyzed retrospectively. Results A boy had difficulty in opening his mouth, crying softly with dyspnea and spitting after birth. The boy had a small jaw and the mouth could not be fully opened. His fingers of hands and toes were slender, and the elbow joint, the middle finger and the ring finger of both hands could not be straightened. He had increased muscle tension in the extremities. The sucking and foraging reflexes were not elicited. The whole exome sequencing showed a novel compound heterozygous variations in CRLF1 gene, among which the frameshift variation of c.829_847del was from the father and the frameshift variation of c.713delC was from the mother. The compound heterozygous variation in this child has not been reported, but was determined to be harmful by bioinformatics analysis. According to the guidelines of the American College of Medical Genetics and Genomics, it was identified as Class Ⅰ pathogenic variant and Class Ⅱ possible pathogenic variant. The patient was eventually diagnosed with CS. Conclusions The main characteristics of CS are fever, flexion deformity, typical facial features, feeding and breathing difficulties, which may lead to sudden neonatal death. This is the first case of CS in China and it expands the spectrum of CRLF1 pathogenic variants.

Key words: Crisponi syndrome; CRLF1 gene; cold induced sweating syndrome