A team of clinicians and scientists from Ireland, Romania, Greece and India have assembled a catalogue of inherited autosomal recessive disorders and 111 pathogenic variants found in the Roma population. The study, led from the Irish team, hope that this will assist the medical and scientific community to make prompt diagnoses and ultimately to improve care. Adaptation of a targeted genetic approach could facilitate timely and cost-effective diagnoses in this population.
Congratulations to the lead author Dr Shauna Quinn working with Professor Sally Ann Lynch, Dr Kathleen Gorman, Prof Ellen Crushell and Prof Andrew Green from the UCD School of Medicine and UCD Academic Centre on Rare Diseases, as well as all those involved, in their recently published paper in the European Journal of Medical Genetics, titled ‘Catalogue of inherited autosomal recessive disorders found amongst the Roma population of Europe’.
Objective
Clinicians and scientists with experience in managing and diagnosing rare diseases in this population in Ireland, Romania and Greece have developed a comprehensive catalogue of autosomal recessive inherited disorders found in the Roma population. A fruitful collaboration with Indian colleagues allowed the team to estimate how many of the variants were present in a subset of the Indian population.
Background
The Roma population are an endogamous, genetically isolated, minority population who migrated from North-Western India to Europe from the 10th Century throughout the Byzantine period and continues to the present day. Approximately 10–12 million Romani people reside in segregated settlements in Europe, and smaller populations live in North America and China. In addition to the endogamy, they also practice consanguinity. This has resulted in a higher frequency of rare autosomal recessive disorders some of which are unique to the Roma population. Some disorders result from founder variants whilst others are private variants, occurring within one nuclear family. Most are found as homozygous variants but compound heterozygosity is seen in a number of conditions.
According to the latest Irish census there are 16,000 individuals self-identifying as Roma in the Republic of Ireland.
Methods
The team performed a detailed literature search to identify relevant publications and disease variants described in patients whose ethnicity was described as Roma. In addition, they interrogated data from local clinicians and colleagues in Ireland, Romania and Greece to collect additional unpublished variants which have yet to be reported in the medical literature. Where possible, they have mapped these disorders back to their European country of origin. Furthermore, they searched the variants allele frequencies on ClinVar. The team analysed exome data from New Delhi, India to trace any of these founder variants back their origins.
Results
The team identified 90 distinct autosomal recessive disorders, manifesting as 91 distinct phenotypes and 111 pathogenic disease variants. These include both published (n = 91) and unpublished (n = 20) findings identified in the Roma population in Europe. The Indian exome data revealed that only 12/111 variants were identified. The team noted that 17 of the disorders have been seen in Ireland, reflecting migration from different Roma groups throughout Europe (Romania, Bulgaria, Hungary, Slovakia, Czech Republic and Poland).
Conclusion
The team have assembled a catalogue of inherited autosomal recessive disorders and 111 pathogenic variants found in the Roma population. They hope that this will assist the medical and scientific community to make prompt diagnoses and thereby improve prognosis.
To read the full paper, see here.