PLA2G6-associated late-onset parkinsonism in a Sudanese family

INTRODUCTION

The phospholipase A2 group VI gene (PLA2G6) encodes an enzyme that catalyzes the hydrolytic release of fatty acids from phospholipids. Four neurological disorders with infantile, juvenile, or early adult-onset are associated with PLA2G6 genetic alterations, namely infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (ANAD), dystonia-parkinsonism (DP), and autosomal recessive early-onset parkinsonism (AREP). Few studies in Africa reported PLA2G6-associated disorders and none with parkinsonism of late adult onset.

MATERIAL AND METHODS

The patients were clinically assessed following UK Brain Bank diagnostic criteria and International Parkinson and Movement Disorder Society's Unified Parkinson's Disease Rating Scale (MDS-UPDRS). Brain MRI without contrast was performed. Genetic testing was done using a custom-made Twist panel, screening 34 known genes, 27 risk factors, and 8 candidate genes associated with parkinsonism. Filtered variants were PCR-amplified and validated using Sanger sequencing and also tested in additional family members to study their segregation.

RESULT

Two siblings born to consanguineous parents developed parkinsonism at the age of 58 and 60 years, respectively. MRI showed an enlarged right hippocampus in patient 2, but no overt abnormalities indicative of INAD or iron deposits. We found two heterozygous variants in PLA2G6, an in-frame deletion NM_003560:c.2070_2072del (p.Val691del) and a missense variant NM_003560:c.956C>T (p.Thr319Met). Both variants were classified as pathogenic.

CONCLUSION

This is the first case in which PLA2G6 is associated with late-onset parkinsonism. Functional analysis is needed to confirm the dual effect of both variants on the structure and function of iPLA2β.

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

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.

Methylation of alpha-synuclein in a Sudanese cohort

BACKGROUND

Several studies suggested a significant role of epigenetic changes, including alterations in miRNA, histone modifications, and DNA methylation of α-synuclein (SNCA) in Parkinson's disease (PD) pathogenicity. As of yet, only very few studies have been carried out in this field in Africa and none in Sudan.

MATERIALS AND METHODS

We collected DNA from 172 Sudanese individuals (90 cases, 82 controls) who donated saliva for DNA extraction (mean age of onset: 40.6 ± 22.4 years). A family history of PD was evident in 64 patients. DNA preparation and bisulfite sequencing of SNCA_intron1 was performed as described earlier.

RESULTS

Of the fourteen analyzed CpGs of SNCA_intron1, CpGs 16-23 were hypomethylated in PD (P-value ranged from 0.023 to 0.003). P-values improved, when sporadic cases were excluded from the analysis.

CONCLUSION

We identified the presence of a specific pattern of DNA methylation in a young Sudanese cohort of familial PD, which confirms the importance of the methylation of SNCA_intron1 for PD. This phenomenon appears to be independent of ethnicity, the impact of environmental factors, drug history, or familial clustering.

Neurology training in sub-Saharan Africa: A survey of people in training from 19 countries

OBJECTIVE

To provide a comprehensive understanding of neurology training from the sub-Saharan African perspective.

METHODS

A 40-question survey was distributed to attendees of the 7th annual sub-Saharan African neurology teaching course in Khartoum, Sudan (2015). Themes included the student body, faculty, curriculum, assessment and examinations, technology, and work hours and compensation.

RESULTS

Of 19 responding countries, 10 had no formal neurology training programs; Burkina Faso, Cameroon, Republic of the Congo, and Mozambique had an adult neurology program; Ethiopia, Madagascar, Nigeria, Senegal, and South Africa had adult and pediatric neurology programs (training duration range = 3-6 years). There was a median of 2.5 full-time neurologists on the teaching faculty at the respondents' training institutions (neurologists on-faculty:in-country ratio = 0.48), with the lowest ratios in Sudan and Nigeria. Neurology was perceived to be a competitive specialty for entrance in 57% of countries, with 78% of respondents reporting a requisite entrance examination. Ninety-five percent had access to a personal smartphone, 62% used the Internet more than occasionally, and 60% had access to online neurology journals. The average number of weekly work hours was 51 (range = 40-75), and average monthly salary among those earning income was 1,191 USD (range = 285-3,560). Twenty percent of respondents reported paying for training. The most common barriers to neurology postgraduate education were few training programs and lack of training in neurodiagnostic tests. Among 17 reporting countries, there is an estimated average of 0.6 neurologists per million people.

INTERPRETATION

Neurology training programs in sub-Saharan Africa are relatively limited in number and have several unmet needs including a small cadre of faculty and an opportunity to standardize curricula and financing of programs. Ann Neurol 2016;79:871-881.

Helicobacter pylori and intestinal metaplasia with its subtypes in the gastric antrum in a Saudi population

BACKGROUND

There is a close association between intestinal metaplasia (IM) and the development of gastric cancer as well as a relationship between Helicobacter pylori, IM, and gastric cancer. Our aim was to study the frequency and subtypes of IM in a Saudi population with dyspepsia, a population with a low prevalence of gastric cancer.

METHODS

Endoscopic antral biopsy specimens were histologically studied for the presence of IM and H. pylori in consecutive patients who underwent upper gastrointestinal endoscopy for evaluation of dyspepsia. Hematoxylin and eosin and Giemsa stain were used to study IM, inflammation, and H. pylori, whereas Alcian blue, pH 2.5/periodic acid-Schiff and high iron diamine/Alcian blue, pH 2.5, were used to study IM subtypes.

RESULTS

Seven hundred and seventy-eight consecutive patients were recruited in this study, 415 men and 363 women, with a mean age of 43 +/- 17.6 years. Of the 778 patients, IM was identified in 118 (15.2%). The mean ages of patients with IM (48.8 +/- 18.7) and without IM (41.9 +/- 17.4) were statistically significant (P < 0.0001), whereas the patients' sex did not influence the presence of IM. Most had type-I IM (59.3%), whereas 26.3% and 14.4% had types II and III, respectively. The overall rate of infection with H. pylori was 75.4%. There was no difference in the frequency of IM in patients with or without H. pylori (15.5% versus 14.1%; P = 0.65). Of the 118 patients with IM, the 91 patients (77.1%) who also had H. pylori were older (55 +/- 23 years) than those without H. pylori (47 +/- 17 years, P = 0.05).

CONCLUSION

This study has documented mainly that the prevalence of IM and IM subtype III is low in our population. Furthermore, we found no significant relationship between a high rate of H. pylori infection with either IM in general or with IM subtype III in particular, possibly accounting for a low incidence of gastric cancer in the Saudi population.

Clinical aspects of malaria in the Asir Region, Saudi Arabia

Three hundred and thirty-four cases of confirmed malaria seen in the Asir Central Hospital, Abha, in southwestern Saudi Arabia, were studied retrospectively. Two hundred and eighty-two of these (84.4%) were Saudis and the majority (72.2%) were living in the lowlands of Tihama. Transmission was found to occur throughout the year, with peaks following the rainy season and in the summer. In Saudis, falciparum malaria is more common than vivax (97.2% vs. 2.8%), while vivax malaria is more commonly seen in expatriates (46.2%). Poor response of falciparum malaria to chloroquine was more prevalent in expatriates than in Saudis (46.4% vs. 23%). Most of the expatriates gave a history of recent travel to countries known to be endemic with resistant malaria. The possibility of the emergence of chloroquine-resistant malaria in the southwestern region of Saudi Arabia was discussed.