Introduction Gitelman syndrome is an inheredited tubular disorder characterized by metabolic alkalosis, hypokaliemia and hypomagnesemia of renal origin and hypocalciuria. The majority of patients with Gitelman syndrome carry inactivating mutations in the SLC 12A3 gene encoding the sodium- chloride cotransporter located in the distal convoluted tubule. The purpose of this report is to describe a new mutation of the SLC12A3 gene in a gypsy boy, mutation of ancient origin that would be specific in this ethnic group and spread throughout Europe.
Case Report A 5 years old male children of Roma origin (Gypsy) was referred to our hospital because asthenia, muscle weakness and hypokaliemia. Both parents are healthy, non consanguineous with normal serum potassium. There were no other family members affected. Relevant biochemical data at diagnosis was: Serum: pH 7.52, bicarbonate 31mmol/L, potassium 2 mEq/L, sodium 136 mEq/L, chloride 97 mEq/L, magnesium 1.6mg/dl, creatinine 0.4 mg/dl, calcium 9 mg/dl. Plasma Renin Activity 13.3 ng/ml/h, Aldosterone 138 pg/ml.
Urinary potassium 51 mEq/L, calcium/creatinine ratio 0.12; Potassium fraccional excretion 20.4%, magnesium fractional excretion 5.9%. Renal ultrasonography and blood pressure was normal.
Genetic study was performed: the patient was homozygous for splice site mutation guanidine to thymine in the first position of intron 9 of SLC12A3 gene (intron 9+1G>T).
Conclusion This finding will facilitate the identification of the genetic defect in further cases of Gitelman syndrome among the gypsy population. This patients exhibit muscle syntoms and asthenia althroug the disease is not particulary severe in this ethnic group.