Pedigree Analysis of Familial Primary Concomitant Horizontal Strabismus in Northern India
- 10 August 2017
- journal article
- research article
- Published by Taylor & Francis Ltd in Strabismus
- Vol. 25 (4), 200-213
- https://doi.org/10.1080/09273972.2017.1350865
Abstract
Purpose: Familial clustering of common forms of primary strabismus like esotropia (ET) and exotropia (XT) is observed in a proportion of the strabismus cohort. The genetic components of this remain unidentified. Linkage studies have demonstrated susceptibility locus for primary strabismus at the STBMS1 locus on 7p22.1 as well as other loci on 4q28.3 and 7q31.2. Recently next generation sequencing (NGS) technology has emerged as a powerful tool in discovery genomics and a large number of novel disease-causing variants are being reported. In this study, we recruited informative families for subsequent genetic analysis for disease-causing variant identification. Methods: All consecutive families with two or more affected members with primary concomitant horizontal strabismus were prospectively recruited at the ophthalmic outpatients department (OPD) of Lady Hardinge Medical College, New Delhi, from August 2014 to February 2017. Detailed phenotypic evaluation and pedigree documentation was performed. Results: Of the 39 recruited families of north Indian origin, 18 families each had affected family members demonstrating either ET or XT. 100% concordance of the phenotype in the affected family members was observed in these families. While vertical transmission was observed in 17/18 families with XT, 7 with ET had affected members across one generation, 2 demonstrated consanguineous pedigree, and 2 comprised identical twin families. In 3 families, a combination of ET and XT was noted. This comprised one family with the ET and XT patients being from 2 separate arms of the family related by marriage, one family where one sibling had XT and the other had ET, and another family where the maternal aunt of the affected proband with ET had XT. Conclusions: Subjects with familial primary concomitant strabismus recruited in this study may provide a valuable resource to unravel the genetic determinants of this condition, which is a common disorder of early childhood with high ophthalmic morbidity.Keywords
Funding Information
- No funding (No funding)
This publication has 16 references indexed in Scilit:
- Zur Rekrutierung geeigneter Familien für die Identifikation ursächlicher Gene des erblichen StrabismusKlinische Monatsblätter für Augenheilkunde, 2015
- Risk Factors and Genetics in Common Comitant StrabismusJAMA Ophthalmology, 2013
- Factors related to impaired visual orienting behavior in children with intellectual disabilitiesResearch in Developmental Disabilities, 2012
- Chromosomes 4q28.3 and 7q31.2 as New Susceptibility Loci for Comitant StrabismusInvestigative Ophthalmology & Visual Science, 2009
- Common Forms of Childhood Strabismus in an Incidence CohortAmerican Journal of Ophthalmology, 2007
- A strabismus susceptibility locus on chromosome 7pProceedings of the National Academy of Sciences of the United States of America, 2003
- Genetic aspects of strabismusArquivos Brasileiros de Oftalmologia, 2002
- Congenital esotropia in Olmsted County, MinnesotaOphthalmology, 1998
- Associations Between Siblings for Esotropia and ExotropiaAmerican Journal of Ophthalmology, 1996
- Risk Factors for Esotropia and ExotropiaAmerican Journal of Ophthalmology, 1994