Awareness of consanguineous marriage burden and willingness towards premarital genetic testing in Sudan: a national cross-sectional study.

Background: Despite the widespread practice of consanguinity in Sudan, there is a lack of exploration into the community's awareness of its health implications on offspring and their overall attitude towards consanguineous unions. Aim: This study aimed to evaluate the community's awareness of the possible health adversities of consanguinity on children and assess the effect of knowledge level on the prevailing attitude towards this practice in Sudan. Methods: From August to December 2018, data were collected from adults aged 18 years and above in five provinces of Sudan regardless of their marital status. The analysis involved both descriptive and multivariate statistical techniques. Results: This study revealed a consanguinity rate of 30.2%. Despite a high awareness level (73.7%) regarding the effects of consanguineous marriage on the health of the offspring, a moderately negative attitude towards this practice (63.9%) was observed. Conclusion: The discordance between the high consanguinity rate in the Sudanese population and the moderately negative attitude suggests a potential persistence of this practice in the future. Without the implementation of educational programs and the provision of genetic counselling services to consanguineous couples, the prevalence of consanguinity is likely to endure.

A novel missense variant in the ATPase domain of ATP8A2 and review of phenotypic variability of ATP8A2-related disorders caused by missense changes.

ATPase, class 1, type 8 A, member 2 (ATP8A2) is a P4-ATPase with a critical role in phospholipid translocation across the plasma membrane. Pathogenic variants in ATP8A2 are known to cause cerebellar ataxia, impaired intellectual development, and disequilibrium syndrome 4 (CAMRQ4) which is often associated with encephalopathy, global developmental delay, and severe motor deficits. Here, we present a family with two siblings born from a consanguineous, first-cousin union from Sudan presenting with global developmental delay, intellectual disability, spasticity, ataxia, nystagmus, and thin corpus callosum. Whole exome sequencing revealed a homozygous missense variant in the nucleotide binding domain of ATP8A2 (p.Leu538Pro) that results in near complete loss of protein expression. This is in line with other missense variants in the same domain leading to protein misfolding and loss of ATPase function. In addition, by performing diffusion-weighted imaging, we identified bilateral hyperintensities in the posterior limbs of the internal capsule suggesting possible microstructural changes in axon tracts that had not been appreciated before and could contribute to the sensorimotor deficits in these individuals.

A novel missense variant in the ATPase domain of ATP8A2 and review of phenotypic variability of ATP8A2-related disorders caused by missense changes.

ATPase, class 1, type 8A, member 2 (ATP8A2) is a P4-ATPase with a critical role in phospholipid translocation across the plasma membrane. Pathogenic variants in ATP8A2 are known to cause cerebellar ataxia, mental retardation, and disequilibrium syndrome 4 (CAMRQ4) which is often associated with encephalopathy, global developmental delay, and severe motor deficits. Here, we present a family with two siblings presenting with global developmental delay, intellectual disability, spasticity, ataxia, nystagmus, and thin corpus callosum. Whole exome sequencing revealed a homozygous missense variant in the nucleotide binding domain of ATP8A2 (p.Leu538Pro) that results in near complete loss of protein expression. This is in line with other missense variants in the same domain leading to protein misfolding and loss of ATPase function. In addition, by performing diffusion-weighted imaging, we identified bilateral hyperintensities in the posterior limbs of the internal capsule suggesting possible microstructural changes in axon tracts that had not been appreciated before and could contribute to the sensorimotor deficits in these individuals.

Bi-allelic PRRT2 variants may predispose to Self-limited Familial Infantile Epilepsy.

Heterozygous PRRT2 variants are frequently implicated in Self-limited Infantile Epilepsy, whereas homozygous variants are so far linked to severe presentations including developmental and epileptic encephalopathy, movement disorders, and intellectual disability. In a study aiming to explore the genetics of epilepsy in the Sudanese population, we investigated several families including a consanguineous family with three siblings diagnosed with self-limited infantile epilepsy. We evaluated both dominant and recessive inheritance using whole exome sequencing and genomic arrays. We identified a pathogenic homozygous splice-site variant in the first intron of PRRT2 [NC_000016.10(NM_145239.3):c.-65-1G > A] that segregated with the phenotype in this family. This work taps into the genetics of epilepsy in an underrepresented African population and suggests that the phenotypes of homozygous PRRT2 variants may include milder epilepsy presentations without movement disorders.