Clinical and genetic findings in patients with congenital cataract and heart diseases

Abstract

Background: Congenital cataract (CC) and congenital heart disease (CHD) are significant birth defects. In clinical practice, the concurrence of CC and CHD is frequently observed in patients. Additionally, some monogenic diseases, copy number variation (CNV) syndromes, and diseases associated with intrauterine infection involve both cataract and heart defects. However, little is known about the association between CC and CHD. Here, we characterised the demographic, clinical, and genetic features of patients with CC and heart defects.

Methods: Medical records for 334 hospitalised patients diagnosed with CC were reviewed. Demographic and clinical features of patients with CC with and without CHD were compared. Clinical and genomic information for patients with 'cataract' and 'cardiac defects' were reviewed from Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources (DECIPHER). Microarray-based comparative genomic hybridisation and whole-exome sequencing were performed in 10 trio families with CC and CHD to detect de novo genomic alterations, including copy number variants and single nucleotide changes.

Results: In a retrospective analysis of 334 patients with CC over the past 10 years at our hospital, we observed a high proportion of patients (41.13%) with CHD (including innocent CHD, which reported as left-to-right shunt in echocardiography test). The CC with CHD group had higher incidences of preterm birth and Down's syndrome than the CC without CHD group. Atrial septal defect was the most frequent heart defect. A total of 44 cases with cataracts and heart diseases were retrieved from Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources (DECIPHER). In total, 52 genomic alterations were reported, 44% of which were de novo germline variants. In the 10 trio families with CC and CHD, we found de novo CNVs responsible for two well-known chromosomal disorders and identified a novel pathogenic mutation in GJA8 responsible for CC.

Conclusions: We observed significant associations between CHD and CC in our 10-year patient cohort. Based on the cohort and data from DECIPHER, developmental syndromes in some patients were due to genetic defects, thus explaining the concurrence of CC and CHD. Additionally, we detected de novo mutations as an independent cause of cataracts. Our findings suggest that developmental syndromes in patients with CC deserve more attention in clinical practice by ophthalmologists.

Keywords: Atrial septal defect; Congenital cataract; Congenital heart diseases; DECIPHER; Down’s syndrome; Microarray-based comparative genomic hybridisation; Whole exome sequencing.

Fig. 1

Types of heart defects in patients with congenital cataracts in our 10 years cohort study

Fig. 2

Demographic and genetic characters of patients with CC and CHD in DECIPHER. A Gender composition of 44 patients. B Types of variants detected in patients. C Chromosome distribution of variants. D Types of cardiac defects in patients

Fig. 3

Pathogenic genomic alterations detected in family-trios with CC and CHD. A 21q11.2-q22.3 duplication detected using aCGH in patient 1. B 22q11.21 deletion detected by WES in patient 2. C GJA8 missense mutation in patient 3