Analysis of Mutations of Two Gitelman Syndrome Family SLC12A3 Genes and Proposed Treatments Using Chinese Medicine

Objective： To determine the gene location of two Gitelman syndrome （GS） family SLC12A3 genes and explore treatments using Chinese medicine （CM） prescriptions. Methods： In order to locate the two GS mutations, samples were collected from 11 people from two different pedigrees for direct genetic sequencing and comparison of the 26 exons of SLC12A3. Furthermore, the change of serum potassium was monitored throughout the therapy and those two probands undertook a sequential superposition of Western medicine （including potassium, Panangin and potassium-sparing diuretics） with CM prescription based on Buyang Huanwu Decoction （补阳还五汤） and Sijunzi Decoction （四君子汤）. The treatment included three stages, oral potassium chloride for the first 2 weeks （stage 1）, potassium-sparing diuretic and Panangin with potassium chloride for the next 2 weeks （stage 2）, CM along with the medicine in stage 2 for the final 2 weeks （stage 3）. Results： The three mutations occurring in proband 1 from pedigree 1 were Thr60Met, 965-1_976de113ins12 （small indels mutation） and Ala122Ala （homozygous silent mutation）. Likewise, three mutations, Asn359Lys, Thr382Met and Arg913GIn, appeared in the proband 2 from pedigree Ⅱ. The serum potassium levels increasing from baseline to sequential stages were 1.63 mmol/L （baseline）, 2.5 mmol/L （stage 1）, 3.1 mmol/L （stage 2） and 3.9 mmol/L （stage 3） in the proband 1, and 2.8 mmol/L （baseline）, 3.1 mmol/L （stage 1）, 3.5 mmol/L （stage 2） and 4.3 mmol/L （stage 3） in the proband 2, respectively. The symptoms （numbness of limbs, weakness, palpitations, etc.） of both probands were all alleviated. Conclusions： The mutations of both GS pedigrees can be defined as compound heterozygous mutations, most of which are known as missense mutations. Applying CM could be an appropriate choice for future intervention of GS.