Gaucher disease in Syrian children: common mutations identification, and clinical futures

Mapping the Diverse Genetic Disorders and Rare Diseases Among the Syrian Population: Implications on Refugee Health and Health Services in Host Countries

The aim of this systematic review is to provide physicians and researchers with a comprehensive list of reported genetic disorders in patients of Syrian origin-those who have become part of the largest displaced population globally-and to highlight the need to consider migrant population-based risk for the development of genetic disease control and prevention programs. This review was performed based on the 2015 PRISMA and the international prospective register of systematic reviews. The present review reports on a total of 166 genetic disorders (only 128 reported on OMIM) identified in the Syrian population. Of these disorders, 27% are endocrine-, nutritional- and metabolic-related diseases. Second to metabolic disorders are congenital malformations, deformations and chromosomal abnormalities. Diseases of the blood and the blood-forming organs accounted for 13% of the total genetic disorders. The majority of the genetic disorders reported in Syrian patients followed an autosomal recessive mode of inheritance. These findings are a reflection of the high rates of consanguineous marriages that favor the increase in incidence of these diseases. From the diseases that followed an autosomal recessive mode of inheritance, 22% are reported to be only present in Syria and other regional countries. Twelve of these genetic diseases were identified to be strictly diagnosed in individuals of Syrian origin. The present systematic review highlights the need to develop programs that target genetic disorders affecting Syrian migrants in host countries. These programs would have potential financial and economic benefits, as well as a positive impact on the physical and mental health of members of the Syrian refugee community and those of their host societies. In turn, this would decrease the burden on the health systems in host countries.

Clinical and Genetic Varieties of Gaucher Disease in Iraqi Children

Gaucher disease (GD), which is due to a deficiency in the lysosomal enzyme β-glucocerebrosidase, is a rare genetic disorder. It is characterized by a wide variety of clinical manifestations and severity of symptoms, making it difficult to manage. A cross-sectional hospital-based genetic study was undertaken with 32 pediatric patients. We recruited 21 males and 11 females diagnosed with GD, with a male-to-female ratio of 1.91:1. The mean age of the study population was 8.79 ± 4.37 years with an age range from 8 months to 17 years. We included patients on clinical evaluation from 2011 to 2019. An enzyme assay test was used to measure β-glucosidase enzyme activity in leukocytes and the GBA gene study was performed by polymerase chain reaction technique. We found GD type 1 in 27 (84.37%) participants, GD type 3 in five (15.63%) participants, while none classified as GD type 2. The dominant mutation in GD 1 was N370S in 81.5%, of which two-thirds were homozygous. The second common mutation in this type of disease (L444P) was present in nine cases (40.9%), two of whom were homozygous (9.9%). Meanwhile, R463C was present in six cases (27.27%), of whom one was homozygous. In GD 3, the dominant mutation was L444P as seen in 80% of the patients followed by N370S and R463C in 20%. This study shows that the most common mutant allele in this study was N370S, followed by L444P. Further large-scale studies with more advanced designs are recommended to explore the sequences of GBA genes.

Twenty- five years of biochemical diagnosis of Gaucher disease: the Egyptian experience

BACKGROUND

Gaucher disease is a rare multi-systemic metabolic disorder resulting from the deficiency of acid β-glucosidase activity, with consequent accumulation of glucocerebroside. Less than 15% of mean normal acid β-glucosidase activity in leukocytes is the gold standard for the diagnosis of Gaucher disease, and is generally supplemented by a massive elevation in chitotriosidase activity. We report here our experience in the biochemical diagnosis of Gaucher disease by showing the heterogeneity of the activity of enzymes over 25 years from 1993-2017, through the analysis of 5128 clinically suspected Gaucher disease cases referred to the Biochemical Genetics Department, National Research Centre, as the main reference lab in Egypt for the diagnosis of Inherited Metabolic Disorders.

METHODS

Acid β-glucosidase and chitotriosidase activities were measured in all referred cases. Sphinogmylinase activity was estimated for all cases with normal β-glucosidase activity and moderate elevation of chitotriosidase.

RESULTS

Out of the 5128 suspected cases, 882 (17%) showed a deficiency in acid β-glucosidase activity, accompanied by a raised chitotriosidase activity, ranges (213-66700 umol/l/h) and mean (7255 umol/l/h). Deficient chitotriosidase activity was found in 9 patients (1%) with low β-glucosidase. 451 cases were diagnosed with acid sphingomyelinase deficiency patients (8.8%).

CONCLUSION

Other biochemical markers are needed in addition to chitotriosidase for the diagnosis and follow up. Molecular testing was done to a relatively small number but needs to be done to all diagnosed patients as many mutations are known to predict the course of the disease.