A Rare Case of Mosaic Ring Turner Syndrome with Horseshoe Kidney.

Rearranged X chromosomes in Turner syndrome (TS) generally present with a mild phenotype, but in cases of ring X chromosomes, the incidence of intellectual disability and other congenital abnormalities can be significantly higher depending on the size of the ring and the involvement of X-inactive specific transcript (XIST) region. Here, we report a 17-year-old female who was referred for a cytogenetic analysis because of primary amenorrhoea. The patient, of normal intelligence, had been found to have traits of TS, especially short stature and some rare findings such as horseshoe kidney and short fourth toe. Cytogenetic analysis showed a mosaic 45, X/46, X and r(X) karyotype. Fluorescence in situ hybridisation analysis using sex chromosome probes permitted us to identify the marker as a ring X chromosome, detected in 30% of cells. The r(X) might include the XIST locus, which would have caused X-inactivation of this abnormal ring chromosome leading to mild phenotype in our patient but with atypical features present in the form of horseshoe kidney and short fourth toe.

Nonclassic congenital adrenal hyperplasia misdiagnosed as Turner syndrome.

We present a patient with nonclassic congenital adrenal hyperplasia (NCAH) misdiagnosed as mosaic Turner syndrome. She presented with complaints of primary infertility. Short stature, the presence of facial hair and hoarse voice was also noted. She had primary amenorrhea and was advised for karyotype at 16 years of age, which was reported as 45, X[20]/46, XX[80], stating her as a case of mosaic Turner syndrome. Clitoroplasty was done at 21 years of age for clitoromegaly, which was noticed during puberty. The diagnosis of mosaic Turner could not explain the virilization. Therefore, we repeated the karyotype, which revealed 46, XX in more than 100 metaphases and was sufficient to exclude mosaicism. Furthermore, the endocrinological evaluation revealed high testosterone level with a normal 17 alpha-hydroxyprogesterone (17-OHP). The presence of pubertal onset virilization with a karyotype of 46, XX and raised testosterone level with normal 17-OHP level, raised the suspicion of NCAH for which adrenocorticotropic hormone stimulation test was done which confirmed the diagnosis of NCAH.