Kuwait is a small Arabian Gulf country with a high rate of consanguinity and where a national newborn screening program was expanded in October 2014 to include a wide range of endocrine and metabolic disorders. A retrospective study conducted between January 2015 and December 2020 revealed a total of 304,086 newborns have been screened in Kuwait. Six newborns were diagnosed with classic homocystinuria with an incidence of 1:50,000, which is not as high as in Qatar but higher than the global incidence. Molecular testing for five of them has revealed three previously reported pathogenic variants in the CBS gene, c.969G>A, p.(Trp323Ter); c.982G>A, p.(Asp328Asn); and the Qatari founder variant c.1006C>T, p.(Arg336Cys). This is the first study to review the screening of newborns in Kuwait for classic homocystinuria, starting with the detection of elevated blood methionine and providing a follow-up strategy for positive results, including plasma total homocysteine and amino acid analyses. Further, we have demonstrated an increase in the specificity of the current newborn screening test for classic homocystinuria by including the methionine to phenylalanine ratio along with the elevated methionine blood levels in first-tier testing. Here, we provide evidence that the newborn screening in Kuwait has led to the early detection of classic homocystinuria cases and enabled the affected individuals to lead active and productive lives.

Mitochondrial disorders are genetic conditions those faces great challenge in the accurate diagnoses due to extensive clinical heterogeneity associated with it. Mitochondria are the only cellular organelles containing their own genome and their functions are governed by both the nuclear and maternally inherited mitochondrial genomes, thus mitochondrial disease could follow all possible modes of inheritance adding to the complexity of diagnosis. Even though the prevalence of the mitochondrial disease has been studied in various parts of the world, the data regarding their prevalence in the Middle East population remains very limited. However, novel mitochondrial disease genes have been identified within the highly consanguineous Arab Middle East population, with the help of novel genetic technologies including the high throughput next-generation sequencing, leading to the identification of important founder mutations underlying several mitochondrial disorders. Furthermore, novel variants in mitochondrial disease genes help in expanding the spectrum of clinical phenotypes studied. The enrichment of reported phenotypes could enhance targeted gene panels leading to a rapid and precise genetic diagnosis facilitating genetic counseling. The aim of this review is to highlight the impact of next-generation sequencing on mitochondrial disease diagnosis in the Middle East population, particularly in identifying novel candidate genes and founder mutations.

Newborn screening for very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency in Kuwait was initiated in October 2014. Over a 7-year period (January 2015 to December 2021), 43 newborns were diagnosed with VLCAD deficiency out of 356,819 screened, corresponding to an incidence of 1:8290 and 1:5405 among only Kuwaiti newborns. This study represents the first comprehensive review of newborn screening for VLCAD deficiency in Kuwait. The screening process begins with the detection of elevated blood C14:1 levels in dried blood spots, followed by confirmatory testing using dried blood spots acylcarnitine profiling, with or without molecular testing. Furthermore, this study demonstrates that incorporating the C14:1/C2 ratio as a supplementary marker in first-tier testing alongside C14:1 improves the positive predictive value (PPV) of the current newborn screening for VLCAD deficiency. Adding molecular genetic testing for known VLCAD variants as a second-tier strategy to the national program is also recommended to further enhance specificity and improve PPV. Our findings provide evidence that the expanded newborn screening program in Kuwait has successfully facilitated the early detection of VLCAD deficiency, preventing death and disability in affected infants.

Background: Infantile‐onset cardiomyopathy due to mitochondrial dysfunction is a severe condition frequently associated with poor prognosis. Biallelic pathogenic variants in ELAC2 , an essential mitochondrial tRNA processing gene, have been implicated in this phenotype. This study investigates the clinical and genetic spectrum of ELAC2 ‐related disease in a national cohort from Kuwait. Methods: We conducted a retrospective cohort study using data from the Kuwait Medical Genetics Center registry, including individuals with genetically confirmed or clinically suspected ELAC2 ‐related cardiomyopathy. Clinical, metabolic, and molecular data were reviewed. Exome sequencing or targeted mutation testing was performed in affected individuals and at‐risk family members. Results: A total of 34 individuals from 23 consanguineous families were identified, of whom 30 were genetically confirmed to harbor the homozygous ELAC2 founder variant c.460T>C; p.(Phe154Leu). All individuals presented in infancy with severe cardiomyopathy and refractory lactic acidosis. Neurological involvement was observed in 39% of cases. The majority exhibited hypertrophic cardiomyopathy, with variable dilated features and pericardial effusion. The disease course was fatal in all, with most patients dying in infancy. Conclusion: This is the largest single‐country cohort reported to date with ELAC2 ‐related mitochondrial cardiomyopathy, raising the global case total to over 70. The uniform presence of the Phe154Leu variant across unrelated Bedouin families highlights a strong founder effect. Given the rapid disease progression and high mortality, we recommend targeted ELAC2 screening in infants with idiopathic cardiomyopathy and persistent lactic acidosis, particularly in consanguineous populations. Premarital carrier testing and early family counseling should be prioritized to support preventive strategies.