# Analysis of the Body Mass Index of Latino Patients With Bardet-Biedl Syndrome

## TL;DR

This study explores how genetic mutations in Bardet-Biedl syndrome relate to obesity in Latino patients, finding a strong link between BBS1 mutations and higher obesity rates.

## Contribution

The study identifies a specific association between BBS1 mutations and increased obesity prevalence in a Latino cohort with Bardet-Biedl syndrome.

## Key findings

- Most patients with BBS1 mutations were obese, compared to those with BBS7 or BBS19 mutations.
- Homozygous and compound heterozygous mutations were linked to more severe obesity.
- Male patients were more frequently overweight, though gender differences were not statistically significant.

## Abstract

Introduction: Bardet-Biedl syndrome (BBS) is a rare, autosomal recessive disorder characterized by multi-systemic manifestations, including truncal obesity, rod-cone dystrophy, polydactyly, and learning disabilities. The syndrome is associated with mutations in at least 28 genes, with BBS1 being the most common. This study investigates the correlation between body mass index (BMI) and specific genetic mutations in a cohort of 27 Latino patients with BBS.

Methods: A chart review of 27 patients with BBS was conducted. Comprehensive ophthalmic evaluations, including best corrected visual acuity (BCVA), optical coherence tomography, and electroretinography, were performed. Genetic screening was conducted using next-generation sequencing with a focus on BBS1, BBS7, and BBS19 mutations. BMI was classified into normal, overweight, and obese categories. Statistical analyses (chi-square and Kruskal-Wallis test) were used to evaluate the data.

Results: The cohort had a mean age of 39 years, with 21 patients (77.8%) carrying mutations in the BBS1 gene. Among the cohort, a total of 14 patients (51.9%) were classified as obese, 10 (37.0%) as overweight, and three (11.1%) as normal weight. Obesity was most common in patients with BBS1 mutations, with 11 obese patients (78.6%) carrying BBS1 mutations, while patients with BBS7 and BBS19 mutations exhibited lower rates of obesity. Among obese patients, 10 (71.4%) were homozygous for mutations in the associated genes, and three (21.4%) were compound heterozygotes. Gender did not show statistically significant differences in obesity prevalence; however, male patients were more frequently overweight.

Conclusion: This study confirms a strong association between BBS1 mutations and obesity in BBS patients, with homozygous and compound heterozygous mutations contributing to more severe clinical manifestations. Further research is required to better understand the genotype-phenotype relationship and to explore the role of environmental factors, such as physical activity, in modifying obesity outcomes. Larger, more diverse studies are needed to validate these findings and to develop targeted therapeutic strategies for BBS-related obesity.