hypophosphatemia

Objective: This case study presents a young female patient diagnosed with symptomatic electrolyte disturbances, later confirmed as Gitelman syndrome (GS). It highlights the underlying pathophysiology and emphasizes the importance of its proper management. Background: GS is a rare genetic disorder affecting kidney electrolyte reabsorption, leading to symptoms like weakness, muscle cramps, fatigue, nausea, and vomiting. Diagnosis involves lab tests and genetic confirmation, with treatment comprising electrolyte supplementation and medications. Ongoing management is vital to prevent complications. Case presentation: A 23-year-old Caucasian female presented to the ED with sudden weakness in all extremities, thirst, and lightheadedness. Lab results showed hyperglycemia 166 (70-100 mg/dL),severe hypokalemia 1.1 (3.6-5.1 mmol/L), mild hypercalcemia 11 (8.9-10.4 mg/dL), and severe hypophosphatemia 0.6 (2.3-7.0 mg/dL). Incidentally, she had prior hypokalemia history from a motor accident hospitalization and managed it with KCl for a year but stopped when symptoms improved. She was treated with electrolyte replacement and discharged with oral potassium. Five days later, she returned with severe hypokalemia 1.3, mild hypercalcemia 10.7, and severe hypophosphatemia 0.6. A 24-hour urinary test showed distal convoluted tubulopathy indicative of GS. She was treated with replacement therapy and spironolactone, with instructions for ongoing supplementation and follow-up with a nephrologist. Discussion: GS is mostly caused by mutations in the SLC12A3 gene, affecting the kidneys’ sodium chloride cotransporter function, as confirmed in our patient. Conclusion: While GS has no cure, appropriate treatment with medication and dietary adjustments can enhance patients’ quality of life by maintaining electrolyte balance. Healthcare providers’ awareness is crucial for effective care and complication prevention.

A 46-year-old lady was diagnosed clinically with X-linked hypophosphatemia (XLH) with a rare pathogenic variant detected using exome sequencing. Phosphate-regulating endopeptidase homologous X linked (PHEX) is normally expressed in osteoblasts and osteocytes, and senses phosphate regulation. More than 1000 PHEX variants have been detected to date, which are caused by missense, nonsense, and frameshift mutations in addition to splice variants and copy number changes. The aberration in the PHEX gene leads to the upregulation of fibroblastic growth factor 23 (FGF23), which leads to defects in phosphate metabolism. This results in impaired bone growth and mineralization, short and disproportionate stature, leg bowing, musculoskeletal pain, spontaneous dental abscesses, rickets, and osteomalacia in XLH patients. The spectrum of manifestations differs between pediatric and adult patients. In our case study, two of the patient’s children started showing symptoms at a younger age, unlike their mother. Timely diagnosis and the start of treatment would help in their better management and improved quality of life.