Аңдатпа
Abstract Introduction Turner syndrome (TS) is a chromosomal disorder caused by partial or complete monosomy of the X chromosome, affecting 1 in 2000-2500 live female births. Mosaic forms containing Y-chromosome material (45,X/46,XY) are uncommon and frequently associated with atypical phenotypes, gonadal dysgenesis, and complex metabolic complications. Early recognition of such genetic variants is essential for preventing progressive skeletal and endocrine deterioration. Case presentation We report a 36-year-old woman with Turner syndrome mosaicism (45,X/46,XY) who presented with progressive skeletal deformities, chronic pain, and multiple pathological fractures. Her height was 130 cm, and she exhibited primary amenorrhea and characteristic Turner features, including short stature, webbed neck, and gonadal dysgenesis. She became wheelchair-dependent in 2023 due to progressive bone fragility. Genetic karyotyping confirmed mosaicism 45,X[12]/46,XY[13], with 48% X monosomy and 52% Y-chromosome presence. Clinical Data Included: Endocrine investigations revealed hypophosphatemia (0.27-0.38 mmol/L), elevated parathyroid hormone levels (256.7 pg/mL), and vitamin D deficiency (28.5 ng/mL). Thyroid function tests indicated subclinical hypothyroidism (TSH 5.3 mIU/L). Imaging findings included generalized osteoporosis, multiple pelvic and femoral neck fractures in consolidation, and bilateral hip osteoarthrosis (CT and DEXA scan). Despite long-term treatment with denosumab, calcium, and vitamin D supplementation, bone mineral density showed no improvement. FISH analysis confirmed Y-chromosome mosaicism in 65% of lymphocytes, providing a genetic explanation for the severe skeletal phenotype. Discussion The presence of Y-chromosome material in Turner mosaicism may intensify skeletal fragility and endocrine dysfunction through disrupted gonadal steroidogenesis and mineral metabolism. Secondary hyperparathyroidism and phosphate imbalance further exacerbate bone loss. This case illustrates the diagnostic challenges of mosaic TS in adulthood, especially when initial manifestations mimic isolated metabolic bone disease. Multidisciplinary evaluation involving endocrinology, genetics, and orthopedics was crucial for accurate diagnosis and individualized management. Conclusions Turner syndrome mosaicism (45,X/46,XY) with Y-chromosome inclusion represents a rare but clinically significant cause of severe, treatment-resistant osteoporosis. Early cytogenetic testing should be considered in patients with unexplained osteoporosis, primary amenorrhea, and short stature. Timely initiation of hormone replacement therapy, phosphate correction, and careful surveillance for gonadal neoplasia are key to improving quality of life and reducing morbidity.