Bartter Syndrome-Related Variants Distribution: Brazilian Data and Its Comparison with Worldwide Cohorts.

Abstract

BACKGROUND:

Genetic testing is recommended for accurate diagnosis of Bartter syndrome (BS) and serves as a basis for implementing specific target therapies. However, populations other than Europeans and North Americans are underrepresented in most databases and there are uncertainties in the genotype-phenotype correlation. We studied Brazilian BS patients, an admixed population with diverse ancestry.

METHODS:

We evaluated the clinical and mutational profile of this cohort and performed a systematic review of BS mutations from worldwide cohorts.

RESULTS:

Twenty-two patients were included; Gitelman syndrome was diagnosed in 2 siblings with antenatal BS and congenital chloride diarrhea in 1 girl. BS was confirmed in 19 patients: BS type 1 in 1 boy (antenatal BS); BS type 4a in 1 girl and BS type 4b in 1 girl, both of them with antenatal BS and neurosensorial deafness; BS type 3 (CLCNKB mutations): 16 cases. The deletion of the entire CLCNKB (1-20 del) was the most frequent variant. Patients carrying the 1-20 del presented earlier manifestations than those with other CLCNKB-mutations and the presence of homozygous 1-20 del was correlated with progressive chronic kidney disease. The prevalence of the 1-20 del in this BS Brazilian cohort was similar to that of Chinese cohorts and individuals of African and Middle Eastern descent from other cohorts.

CONCLUSION:

This study expands the genetic spectrum of BS patients with different ethnics, reveals some genotype/phenotype correlations, compares the findings with other cohorts, and provides a systematic review of the literature on the distribution of BS-related variants worldwide.

• Authors: Maria Helena Vaisbich, Ana Carola Hebbia Lobo Messa, Andréia Cristiane Rangel-Santos, Juliana Caires de Oliveira Achili Ferreira, Fernanda Andrade M da F Nunes, Andreia Watanabe
• Journal: Nephron (Nephron) Vol. 147 Issue 8 Pg. 478-495 ( 2023) ISSN: 2235-3186 [Electronic] Switzerland
• PMID: 36882007 (Publication Type: Systematic Review, Journal Article)
• Copyright: © 2023 S. Karger AG, Basel.

Chemical References

• Solute Carrier Family 12, Member 1
• CLCNKB protein, human
• Chloride Channels

Topics

• Pregnancy
• Female
• Humans
• Bartter Syndrome (genetics)
• Brazil
• Phenotype
• Mutation
• Solute Carrier Family 12, Member 1 (genetics)
• Chloride Channels (genetics)