Genetic care in geographically isolated small island communities: 8 years of experience in the Dutch Caribbean

Abstract

Worldwide, there are large inequalities in genetic service delivery. In 2011, we established a bi-annual joint pediatric-genetics clinic with a visiting clinical geneticist in the Dutch Caribbean. This retrospective study evaluates the yield of diagnostic testing and the clinical utility of a diagnosis for patients with rare diseases on these relatively isolated, resource-limited islands. A total of 331 patients that were referred to the clinical geneticist between November 2011 and November 2019 and had genetic testing were included in this study. A total of 508 genetic tests were performed on these patients. Microarray, next-generation sequencing gene panels, and single-gene analyses were the most frequently performed genetic tests. A molecularly confirmed diagnosis was established in 33% of patients (n = 108). Most diagnosed patients had single nucleotide variants or small insertions and/or deletions (48%) or copy number variants (34%). Molecular diagnostic yield was highest in patients referred for seizures and developmental delay/intellectual disability. The genetic diagnosis had an impact on clinical management in 52% of patients. Referrals to other health professionals and changes in therapy were the most frequently reported clinical consequences. In conclusion, despite limited financial resources, our genetics service resulted in a reasonably high molecular diagnostic yield. Even in this resource-limited setting, a genetic diagnosis had an impact on clinical management for the majority of patients. Our approach with a visiting clinical geneticist may be an example for others who are developing genetic services in similar settings.

Keywords: caribbean; clinical genetics; clinical utility; diagnostic yield; rare diseases.

FIGURE 1

Molecular diagnostic results. (a) Variant types. (b) Mode of inheritance in patients with small variants (single nucleotide variants or small insertions and/or deletions). (c) Molecular diagnostic yield per primary reason for referral (reason for referral only included if n > 10). (d) Molecular diagnostic yield per type of genetic test (genetic test only included if n > 10). AD, autosomal dominant; AR, autosomal recessive; CA, congenital anomalies; CNVs, copy number variants; CTD, connective tissue disorder; DD/ID, developmental delay and/or intellectual disability (with or without other anomalies); NGS, next‐generation sequencing; NGS, next‐generation sequencing; UPD, uniparental disomy