Background:This study reported a case of micropenis caused by a novel hemizygous
mutation in the ADGRG2 gene, which aimed to expand the understanding of sexual dysplasia
caused by ADGRG2 gene mutation.Case Presentation:We present the clinical data and genetic test results of a patient with micropenis
admitted in September, 2022, to the Tongji Hospital. The patient was a 9-year-10-
month-old male whose chief complaint was the presence of a short penis over a period of three
years. In April 2016, the patient underwent corrective surgery for a clubbed penis. Upon admission
to the study hospital, his height and weight were 145.0 cm (75-90th percentile) and 37.8 kg
(50-75th percentile), respectively, and his BA was 12 years old. His physical characteristics included
a normal face, bilateral testicle size of 2 ml, and penile length of about 3 cm. A gonadotrophin-
releasing hormone-stimulating test revealed normal hypothalamic-pituitary-gonadal axis
function. An HCG stimulation test indicated normal sperm production in the testis. Key abnormalities
from auxiliary examinations included low testosterone and high ACTH, dehydroepiandrosterone
sulfate, androstenedione, and 17-OH-P levels. Genetic testing revealed a new
hemizygous mutation, a splicing mutation in intron 4 of the ADGRG2 gene (ChrX: 19040187
(NM_001079858.3): c.154 + 2T > A, inherited from the mother.Conclusion:This study reported a case of micropenis caused by a new hemizygous mutation in
the ADGRG2 gene. This indicates the importance of genetic testing and gene-guided treatments
to improve prognosis.