Loss of DMRT1 gene in a Mos 45,XY,-9[8]/46,XY,r(9)[29]/47,XY,+idic r(9)× 2[1]/46,XY,idic r(9)[1]/46,XY[1] female presenting with short stature

Ring chromosome formation by intra-strand repairing of subtelomeric double stand breaks and clinico-cytogenomic correlations for ring chromosome 9

Constitutional ring chromosome 9, r(9), is a rare chromosomal disorder. Cytogenomic analyses by karyotyping, array comparative genomic hybridization (aCGH) and whole genome sequencing (WGS) were performed in a patient of r(9). Karyotyping detected a mosaic pattern of r(9) and monosomy 9 in 83% and 17% of cells, respectively. aCGH detected subtelomeric deletions of 407 kb at 9p24.3 and 884 kb at 9q34.3 and an interstitial duplication of 5.879 Mb at 9q33.2q34.11. WGS revealed double strand breaks (DSBs) at ends of 9p24.3 and 9q34.3, inverted repeats at ends of subtelomeric and 9q33.2q34.11 regions, and microhomology sequences at the junctions of this r(9). This is the first report of r(9) analyzed by WGS to delineate the mechanism of ring chromosome formation from repairing of subtelomeric DSBs. The loss of telomeres by subtelomeric DSBs triggered inverted repeats induced intra-strand foldback and then microhomology mediated synthesis and ligation, which resulted in the formation of this r(9) with distal deletions and an interstitial duplication. Review of literature found seven patients of r(9) with clinical and cytogenomic findings. These patients and the present patient were registered into the Human Ring Chromosome Registry and a map correlating critical regions and candidate genes with relevant phenotypes was constructed. Variable phenotypes of r(9) patients could be explained by critical regions and genes of DOCK8, DMRT, SMARCA2, CD274, IL33, PTPRD, CER1, FREM1 for 9p deletions, and the EHMT1 gene for 9q34 deletion syndrome. This interactive registry of r(9) could provide information for cytogenomic diagnosis, genetics counseling and clinical management.

Clinical case report: A case of Turner syndrome with Graves' disease

INTRODUCTION

The incidence of Hashimoto's thyroiditis among patients who have Turner syndrome (TS) has increased, but Graves' disease (GD) in patients with TS is rarely reported. Here we report a rare case of TS with GD accompanied by hypogonadotropic hypogonadism.

PATIENT CONCERNS

We report the case of a 16-year-old girl who complained nervousness, fatigue, marasmus, heat intolerance, sweating, palpitation, and tremor lasting for more than a month. She had no medical history.

DIAGNOSIS

TS was diagnosed of the results of karyotyping demonstrated a gene karyotype of 46, X, i (X)(q10). GD was also diagnosed in this patient following the detection of thyroid function analysis.

INTERVENTIONS

Methimazole was administered after identification of GD. Due to the absence of secondary sex characteristics, the patient was given a conjugated estrogen preparation for 1 year, followed by the addition of estradiol cyproterone tablets for the onset of menstruation.

OUTCOMES

The hyperthyroidism symptoms of the patient had improved both clinically and laboratory tests after methimazole therapy. She was treated with estrogen and estradiol cyproterone, and the uterus and secondary sexual characteristics of the patient developed during 1 year follow-up.

CONCLUSION

TS generally presents as hypergonadotropic hypogonadism. However, hypogonadotropic hypogonadism cannot completely exclude TS. The diagnosis of this disease depends on chromosomal examination. The disease should be detected and treated as early as possible to improve life quality of the patient.