AUTHOR=Milanowski Lukasz M. , Oshinaike Olajumoke , Broadway Benjamin J. , Lindemann Jennifer A. , Soto-Beasley Alexandra I. , Walton Ronald L. , Hanna Al-Shaikh Rana , Strongosky Audrey J. , Fiesel Fabienne C. , Ross Owen A. , Springer Wolfdieter , Ogun Shamsideen Abayomi , Wszolek Zbigniew K. 

TITLE=Early-Onset Parkinson Disease Screening in Patients From Nigeria

JOURNAL=Frontiers in Neurology

VOLUME=Volume 11 - 2020

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.594927

DOI=10.3389/fneur.2020.594927

ISSN=1664-2295

ABSTRACT=Nigeria is one of the most populated countries in the world; however, there is a scarcity of studies in patients with age-related neurodegenerative diseases, such as Parkinson disease (PD). The aim of this study was to screen patients with PD including a small cohort of early onset PD (EOPD) cases from Nigeria for PRKN, PINK1, DJ1, SNCA multiplication, and LRRK2 p.G2019S. 
We assembled a cohort of 109 Nigerian patients with PD from the 4 main Nigerian tribes: Yoruba, Igbo, Edo, and Hausa. Fifteen cases had EOPD (defined as age-at-onset <50 years). All patients with EOPD were sequenced for the coding regions of PRKN, PINK1, and DJ1. Exon dosage analysis was performed with a multiplex ligation-dependent probe amplification assay, which also included a SNCA probe and LRRK2 p.G2019S. We screened for LRRK2 p.G2019S in the entire PD cohort using a genotyping assay. 
In 15 patients with EOPD, 22 variants were observed (PRKN, 9 [40.9%]; PINK1, 10 [45.5%]; and DJ1, 3 [13.6%]). Three (13.6%) rare, nonsynonymous variants were identified, but no homozygous or compound heterozygous carriers were found. No exonic rearrangements were present in the 3 genes, and no carriers of SNCA genomic multiplications or LRRK2 p.G2019S were identified. The PINK1 p.R501Q functional analysis revealed pathogenic loss of function.
More studies on age-related neurodegenerative diseases are needed in sub-Saharan African countries, including Nigeria. Population-specific variation may provide insight into the genes involved in PD in the local population, but may also contribute to larger studies performed in White and Asian populations.