Intrafamilial and interfamilial heterogeneity of PINK1-associated Parkinson's disease in Sudan

• Published in: Parkinsonism & related disorders 2023-06, Vol.111, p.105401-105401, Article 105401
• Main Authors: Bakhit, Yousuf, Ibrahim, Mohamed O., Tesson, Christelle, Elhassan, Ali A., Ahmed, Mohamed Anwer, Alebeed, Mohamed A., Elrasheed, Salma M., Omar, Mawia A., Abubaker, Rayan, Eltom, Khalid, Shaheen, Mutaz T., Ibrahim, Yousuf A., Almak, Murad E., Ali, Hiba A., Abugrain, Ahmed A., Almahal, Mohamed A., MohamedSharif, Abubaker A., Tahir, Mohamed Y., Malik, Sawazen M., Eldirdiri Abdelrahman, Hazim, Khidir, Reem J., Mohamed, Malaz T., Abdalla, Abdelmohaymin, Elsayed, Liena E.O., Lesage, Suzanne, Corvol, Jean-Christophe, Seidi, Osheik, Wüllner, Ullrich
• Format: Article
• Language: English
• Subjects: Age of Onset; Heterogeneity; Homozygote; Humans; Mutation - genetics; Parkinson; Parkinson Disease - genetics; Parkinsonian Disorders - genetics; PINK1; Protein Kinases - genetics; Sudan
• ISSN: 1353-8020; 1873-5126; 1873-5126
• DOI: 10.1016/j.parkreldis.2023.105401

PINK1 is the second most predominant gene associated with autosomal recessive Parkinson's disease. Homozygous mutations in this gene are associated with an early onset of symptoms. Bradykinesia, tremors, and rigidity are common features, while dystonia, motor fluctuation, and non-motor symptoms occur in a lower percentage of cases and usually respond well to levodopa. We investigated 14 individuals with parkinsonism and eleven symptom-free siblings from three consanguineous Sudanese families, two of them multigenerational, using a custom gene panel screening 34 genes, 27 risk variants, and 8 candidate genes associated with parkinsonism. We found a known pathogenic nonsense PINK1 variant (NM_032409.3:c.1366C>T; p.(Gln456*)), a novel pathogenic single base duplication (NM_032409.3:c.1597dup; p.(Gln533Profs*29)), and another novel pathogenic insertion (NM_032409.3:c.1448_1449ins[1429_1443; TTGAG]; p.(Arg483Serfs*7)). All variants were homozygous and co-segregated in all affected family members. We also identified intrafamilial and interfamilial phenotypic heterogeneity associated with PINK1 mutations in these Sudanese cases, possibly reflecting the nature of the Sudanese population that has a large effective population size, which suggests a higher possibility of novel findings in monogenic and polygenic diseases in Sudan. •Most PINK1 mutations were reported in North America, Europe and North Africa.•Some of these known mutations were found in our cohort.•Several findings in our cohort point out to intra-familial and inter-familial heterogeneity.