Detection of Gene Mutation for Patients with McCune- Albright Syndrome and Diagnosis Experience: A Report of Two Cases and Literature Review

Abstract

Background: McCune-Albright Syndrome (MAS) is a rare disease characterized by a broad spectrum of syndromes, including hyperfunctioning endocrinopathies, café-au-lait leisions, and multiple bone fibrous dysplasias. The diagnosis of MAS is usually based on clinical symptoms. However, most of MAS patients may not display typical symptoms, which make the early diagnosis and treatment of MAS difficult. Cases: Patient 1, a 7-year and 4-month-old girl, developed vaginal bleeding with no apparent cause. A Café-au-lait macule patch could be seen on the right trunk. E2 was 914pmol/L. FSH <0.1IU/L, Luteinizing Hormone (LH) <0.1IU/L. Performing ultrasound, there was a cystic mass in the left accessory area with ovarian echo. There were bone abnormalities in the long bones of the extremities. Patient 2, a girl aged 4 years and 9 months, has abnormal enlarged breasts with no obvious cause. There was a cystic mass in the left accessory area with ovarian echo No apparent Café-au-lait macule hyperpigmented skin macule was seen. E2 is 800pg/ml, FSH <0.1IU/L, LH is 0.2IU/L. GNAS mutation were both positive in the cyst tissue but was negative in the peripheral blood. Conclusion: Gene sequencing is the confirmable proof in diagnosis of MAS. Negative GNAS gene mutation results in the peripheral blood and skin cannot completely rule out the possibility of MAS. Biopsy of the lesion tissues, such as ovarian tissue, may present more efficient results. New detection techniques have higher sensitivity and make molecular diagnosis more accurate.