Journal
BMC MEDICAL GENETICS
Volume 18, Issue -, Pages -Publisher
BMC
DOI: 10.1186/s12881-017-0372-0
Keywords
Bardet-Biedl syndrome; BBS1; BBS2 and BBS10 gene variants; Ciliopathy; Renal; ocular and audiovestibular phenotype
Categories
Funding
- Italian Ministry of University and Research [PON03PE_00146_1 2007/2013]
- Regione Campania, Italy [POR Campania FSE 2007/2013]
Ask authors/readers for more resources
Background: Bardet-Biedl syndrome (BBS) is a rare genetic disorder that features retinal degeneration, obesity, polydactyly, learning disabilities and renal abnormalities. The diagnosis is often missed at birth, the median age at diagnosis being 9 years. In the attempt to shed light on BBS and improve its diagnosis and treatment, we evaluated the genotype-phenotype relationship in patients with a molecular diagnosis of BBS. Methods: We analyzed three common BBS genes, BBS1, BBS10 and BBS2, in 25 Italian patients fulfilling the clinical criteria of BBS. In 12 patients, we identified gene-specific biallelic variants and thus correlated genotype to the ophthalmic, renal and audio-vestibular phenotypes. Results: At least one sequence variant was found in 60% of patients. The most common mutated gene was BBS1 followed by BBS10. Of the 17 sequence variants we found, 11 have not previously been associated with BBS. In 12 patients, we identified biallelic pathogenic variants; they had retinitis pigmentosa with early onset of visual impairment. However, retinal dystrophy was less severe in patients with BBS1 than in those with BBS10 variants. Overall, we found a high prevalence of renal dysmorphism and dysfunction. Notably, patients with BBS10 variants had the most severe renal impairment, which resulted in a critical decline in renal function. All the patients who underwent audio-vestibular evaluation had dysfunction of the cochlear outer hair cells, thus confirming the presence of hearing defects. Conclusion: BBS1, BBS2 and BBS10 are major causative genes in Italian BBS patients. BBS10 was associated with the worse outcome in terms of the renal, ocular and audiovestibular phenotypes. Cochlear dysfunction should be included among the hallmarks of BBS.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available