Abstract: SUN Zhong-hui *, LI Ming, GUO Yun-yi, YAO Zhi-rong. *Department of Dermatology, Fengxian District Institute of Dermatology, Shanghai 201408, China Corresponding author: YAO Zhi-rong, Email: zryaosmu@sohu.com 【Abstract】 Objective To make a genetic diagnosis of sporadic neurofibromatosis type 1 with café-au-lait spots as the only presentation in a child. Methods Blood samples were collected from an 8-year-old child patient, his parents, and 100 healthy human controls. The mutation of NFl gene was detected by PCR and direct sequencing． Results No mutation was detected in the NFl gene of the parents or the healthy controls. There was a de novo nonsense mutation c.3520C ＞ T （p. Q1174X） in the NFl gene of the patient, which leaded to a premature termination codon. Conclusions The child with café-au-lait spots as the only manifestation is diagnosed with sporadic neurofibromatosis type 1 by genetic testing. The mutation c.3520C ＞ T （p. Q1174X） may be an underlying cause of neurofibromatosis type 1.

Key words: neurofibromatosis