Reduced penetrance in a large Caucasian pedigree with Stickler syndrome.

Journal Article

In a four-generation Caucasian family variably diagnosed with autosomal dominant (AD) Stickler or Wagner disease, commercial gene screening failed to identify a mutation in COL2A1 or VCAN. We utilized linkage mapping and exome sequencing to identify the causal variant.Genomic DNA samples collected from 40 family members were analyzed. A whole-genome linkage scan was performed using Illumina HumanLinkage-24 BeadChip followed by two-point and multipoint linkage analyses using FASTLINK and MERLIN. Exome sequencing was performed on two affected individuals, followed by co-segregation analysis.Parametric multipoint linkage analysis using an AD inheritance model demonstrated HLOD scores > 2.00 at chromosomes 1p36.13-1p36.11 and 12q12-12q14.1. SIMWALK multipoint analysis replicated the peak in chromosome 12q (peak LOD = 1.975). FASTLINK two-point analysis highlighted several clustered chromosome 12q SNPs with HLOD > 1.0. Exome sequencing revealed a novel nonsense mutation (c.115C>T, p.Gln39*) in exon 2 of COL2A1 that is expected to result in nonsense-mediated decay of the RNA transcript. This mutation co-segregated with all clinically affected individuals and seven individuals who were clinically unaffected.The utility of combining traditional linkage mapping and exome sequencing is highlighted to identify gene mutations in large families displaying a Mendelian inheritance of disease. Historically, nonsense mutations in exon 2 of COL2A1 have been reported to cause a fully penetrant ocular-only Stickler phenotype with few or no systemic manifestations. We report a novel nonsense mutation in exon 2 of COL2A1 that displays incomplete penetrance and/or variable age of onset with extraocular manifestations.

Full Text

Duke Authors

Cited Authors

  • Tompson, SW; Johnson, C; Abbott, D; Bakall, B; Soler, V; Yanovitch, TL; Whisenhunt, KN; Klemm, T; Rozen, S; Stone, EM; Johnson, M; Young, TL

Published Date

  • January 17, 2017

Published In

Volume / Issue

  • 38 / 1

Start / End Page

  • 43 - 50

PubMed ID

  • 28095098

Electronic International Standard Serial Number (EISSN)

  • 1744-5094

International Standard Serial Number (ISSN)

  • 1381-6810

Digital Object Identifier (DOI)

  • 10.1080/13816810.2016.1275018

Language

  • eng