Gitelman syndrome in Gypsy paediatric patients carrying the same intron 9 + 1 G>T mutation. Clinical features and impact on quality of life.
BACKGROUND
Gitelman syndrome is a primary tubular disorder causing hypokalaemic metabolic alkalosis with hypocalciuria. Its prevalence is high in Gypsies, who harbour an identical mutation, intron 9 + 1 G>T, in the SLC12A3 gene.


METHODS
To better define the Gitelman syndrome in Gypsies, the clinical and biochemical features of 34 Spanish paediatric Gypsy patients were analysed. At diagnosis, symptoms, height and weight as well as serum and urinary biochemical data were collected. During a follow-up of 4.5 ± 2.4 years [X ± standard deviation (SD)], therapy, treatment compliance, symptoms, frequency of hospital admissions and, at the last visit, growth and biochemical work-up of 29 patients followed for at least 6 months were analysed. Quality of life items were also assessed by a questionnaire.


RESULTS
Muscle cramps (41%) and asthenia (35%) were the most frequent presenting symptoms. Biochemical data at diagnosis were serum K 2.76 ± 0.46 mEq/L, serum Mg 1.32 ± 0.28 mg/dL, blood pH 7.45 ± 0.06, serum bicarbonate 28.2 ± 2.9 mEq/L, urinary calcium/creatinine ratio 0.03 ± 0.04 mg/mg, fractional K excretion 24.4 ± 17.1% and fractional Mg excretion 8.9 ± 8.3%. During follow-up, Mg and K supplements were prescribed to 79 and 86% of patients, respectively; compliance with treatment was good in 35%. Hospital admission rate was 0.03/patient/month. Muscle cramps were the symptom most often referred by the patients (45%) during the follow-up, and 71% of patients considered their health status as excellent or good. Twenty-one patients stated that their disease did not adversely interfere with their mood or social relationships. Height and weight of patients at diagnosis were -0.60 ± 1.17 and -0.49 ± 1.32 SD, respectively, and improved to -0.44 ± 1.28 (P < 0.05) and 0.18 ± 1.79 SD (P < 0.01) at the last visit.


CONCLUSIONS
Gypsy children with Gitelman syndrome mostly exhibit muscle symptoms and asthenia although the disease is not particularly severe in this ethnic group. Body growth improves with treatment and close follow-up.
Herrero-Morín
José David
JD
Hospital Álvarez Buylla, Mieres, Spain.
Rodríguez
Julián
J
Coto
Eliecer
E
Gil-Peña
Helena
H
Alvarez
Victoria
V
Espinosa
Laura
L
Loris
César
C
Gil-Calvo
Marta
M
Santos
Fernando
F
D000293:Adolescent; D000328:Adult; D001247:Asthenia / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D053579:Gitelman Syndrome / Q000150:complications* / Q000235:genetics*; D006760:Hospitalization; D006801:Humans; D007438:Introns / Q000235:genetics*; D008297:Male; D009120:Muscle Cramp / Q000209:etiology; D009154:Mutation / Q000235:genetics*; D011379:Prognosis; D011788:Quality of Life; D011955:Receptors, Drug / Q000235:genetics*; D006178:Romani People / Q000235:genetics*; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters / Q000235:genetics*; D055815:Young Adult
D011955:Receptors, Drug; C578874:SLC12A3 protein, human; D064486:Solute Carrier Family 12, Member 3; D027981:Symporters