Table 1.
Overview of studies into MNDs in Sub-Saharan Africa∗.
| Article reference | Country and setting | Study design and year | Sample characteristics | Diagnostic criteria and tools used | Disease prevalence | Disease risk factors and genetic determinants identified |
|---|---|---|---|---|---|---|
| Wilmshurst et al. [15] | South Africa; hospital-based |
Case-controlled studies; 1980–2001 |
30 patients: 4 SMA type 1 patients; 16 SMA type 2 patients; 10 SMA type 3 patients. All patients were black South Africans. Six horn cell disease patients were used as controls | Clinical diagnosis | NA | Homozygous deletions of exon 7 or exons 7 and 8 of the SMN1 gene in all patients. Patients were found not to be genetically or phenotypically different from internationally recognised forms of SMA |
|
| ||||||
| Ekenze et al. [16] | Nigeria; hospital-based | Retrospective; 2003–2007 | 8440 patients: 1249 patients (640 men) suffering from neurological disorders (45 y mean age). Ten of these patients were suffering from ALS (4 were men) | NA | 800/100,000 | NA |
|
| ||||||
| Sangaré et al. [17] | Mali; hospital-/laboratory-based | Case-controlled studies | 628 Malians, 120 Nigerians, and 120 Kenyans (healthy individuals) | NA | 1/209 SMA carrier frequency in the SSA patients (mostly Malians) compared to 1/30–50 in Europeans and Asians | Participants had 3 or more copy numbers of SMN1 gene and lacked SMN2 compared to Europeans |
|
| ||||||
| Osuntokun et al. [18] | Nigeria; hospital-based | Retrospective; 1958–1973 | 92 patients with MND: 73 ALS, 9 SMA, and 10 PMA | ENMG, muscle biopsy | 21/100,000 | NA |
|
| ||||||
| Stevens et al. [14] | South Africa; hospital-based | Case study series | 29 SMA patients | Clinical | NA; the study concluded that differences in SMA phenotype in black patients may be due to different molecular/genetic basis mediating the disease among such populations |
65.5% (19/29) homozygous SMN1 deletions in black patients. 47% (4/29) of SMN1 deletions were found in telomeric exon 7 but not exon 8. Also, 14% homozygous NAIP deletions were identified. No gene deletions were found in 35% of patients |
|
| ||||||
| Adam [19] | Kenya; hospital-based | Retrospective; 1978–1988 | 47 MND participants (35 men and 12 women). 18 of these were suffering from ALS (13–80 y olds) | Clinical, 1/3 ENMG | NA | NA |
|
| ||||||
| Kiepiela et al. [20] | South Africa; hospital-/laboratory-based |
Case-controlled studies | South African and Indian SMA patients | Clinical | NA | Genetics: no significant changes in patients' immunoregulatory cells identified |
|
| ||||||
| Kengne et al. [21] | Cameroon; hospital-based | Retrospective; 1993–2001 | 4041 patients; 145 with neurological diseases. Ten out of these were suffering from ALS (8 men and 2 women); mean age = 50.9 y | NA | 250/100,000 of all neurologic consultations; 12% of all neurological cases | NA |
|
| ||||||
| Imam and Ogunniyi [9] | Nigeria; hospital-based | Retrospective; 1980–1999 | 16 ALS patients (15 men and 1 woman), 16–60 y | El Escorial diagnostic criteria | NA | Identified risk factor: trauma in 37.5% of subjects |
|
| ||||||
| Sene et al. [22] | Senegal; hospital-based | Retrospective; 1999-2000 | 33 ALS patients | El Escorial diagnostic criteria, ENMG | NA | NA |
|
| ||||||
| Tekle-Haimanot et al. [23] | Ethiopia; community-based | Cross-sectional; 1986–1988 | 60820 participants (29412 men), 59% < 20 y, 3 MND patients (2 men and 1 woman) | Neurological examinations, screening questionnaire | 5/100,000 | NA |
|
| ||||||
| Labrum et al. [13] | South Africa; hospital-based | Case-controlled studies | 116 SMA patients; 92 of black ancestry, 24 white patients | Clinical (not ENMG) | Carrier frequency of 1/50 in black population but 1/23 in white population | 51% homozygous deletions of SMN1 gene in black patients, as opposed to 95% of patients worldwide |
|
| ||||||
| Wall and Gelfand [24] | Zimbabwe; hospital-based | Retrospective; 1967–1971 | 13 MND patients; 24–55 y | Clinical (not ENMG) | NA | Sensory changes in six participants |
|
| ||||||
| Lumaka et al. [11] | Kinshasha, Congo; hospital-based | Case study | 1 SMA type 1 infant patient | Clinical, ENMG | NA; family history (similar symptomatology in elder brother) | Extreme hypotonia in infancy; homozygous deletions of SMN1; 2 SMN2 alleles present |
|
| ||||||
| Collomb et al. [25] | Senegal; hospital-based | Retrospective; 1960–1968 | 18 ALS patients (17 men and 1 woman), 25–70 y | Clinical (not ENMG) | NA | NA |
|
| ||||||
| Pelleboer et al. [26] | Nigeria; hospital-based | Case study | 1 SMA type 1 infant | Clinical | NA | NA |
|
| ||||||
| Bauer et al. [27] | Tanzania, hospital-based | Case-controlled series; 1993–1997 |
117 SA inpatient admissions and 117 matched controls; 24–77 y | Neurological examination, screening questionnaire | 7/117 in SA group but 0/117 in control group | SA was identified as a risk factor for muscular atrophy |
|
| ||||||
| Ndiaye et al. [28] | Senegal; hospital-based | Case study series | 5 SMA type 1 patients | Clinical, ENMG | NA | Identified risk factors: severe hypotonia in infancy, family history of SMA |
|
| ||||||
| Osuntokun et al. [29] | Nigeria; community-based | Cross-sectional | 18954 participants; 9282 men, 58% < 20 y, 11% > 50 y | Screening questionnaire | MND; 15/100,000 | NA |
|
| ||||||
| Lekoubou et al. [30] | SSA; systematic analysis of associations between MNDs and diabetes mellitus | Retrospective (3 case control and 2 cross-sectional studies) | Up to 2371 ALS cases reviewed | NA | NA | No association between ALS and diabetes mellitus identified |
|
| ||||||
| Abdulla et al. [31] | Sudan; hospital-based | Retrospective; 1993–1995 | 28 MND patients, including 19 ALS patients | Clinical, ENMG | NA | Family history of MND identified in 14% of patients |
|
| ||||||
| Cosnett et al. [32] | South Africa; hospital-based | Retrospective; reviewed 9.5 y of cases | 59 blacks (47.4 y mean age), 9 Indians, 16 whites, 2 coloured patients (54 y mean age for non-black patients) | Clinical, 45% ENMG | The following prevalence values per 100,000 persons were observed for different populations: blacks (0.88), whites (2), coloured (7), Indians (1.4). | NA |
|
| ||||||
| Harries [33] | Ethiopia; hospital-based | Case study series; 1954 | 2 male participants, aged 26 and 30 y | Clinical (no ENMG) | NA | NA |
|
| ||||||
| Meilleur et al. [34] | Mali; hospital/laboratory-based | Case control | Study cohort included 2 spastic paraplegia patients with amyotrophy, 5 extended family members, and 43 unrelated people of the same ethnic group | Clinical | NA | Extended homozygosity at chromosome 19p13.11-q12 (designated as SPG43) in patients but not controls |
|
| ||||||
| Jacquin-Cotton et al. [35] | Senegal; hospital-based | Retrospective; 1960–1969 | 6100 patients; 18 ALS (16 men), 25–70 y | Clinical (no ENMG) | 290/100,000 | NA |
|
| ||||||
| Moosa and Dawood [36] | SSA | Case study series | 45 SMA patients; 15 SMA type 1, 19 type 2, and 9 type 3; infants to 48 month olds; 1 : 1.7 female/male ratio | Clinical, ENMG | NA | Facial weakness in 80% of type 1 patients |
|
| ||||||
| Piquemal et al. [37] | Ivory Coast; hospital-based | Retrospective; 1971–1980 | 4000 patients; 30 ALS (22 men), 50% < 40 y | Clinical (no ENMG). | 750/100,000 | NA |
|
| ||||||
| Landouré et al. [38] | Mali; hospital- and laboratory-based | Case control | Study cohort included 2 spastic paraplegia patients with amyotrophy, 298 Malian controls, and several alleles found in the NHLBI exome sequencing Project database | Clinical | NA | Homozygous missense variation of c.187G>C; p.Ala63Pro, in C19orf12, was observed in the spastic paraplegia patients but not in the 298 Malian control subjects |
∗ALS, amyotrophic lateral sclerosis; ENMG, electroneuromyography; MND, motor neuron disease; NA, not available; PMA, progressive muscular atrophy; SMA, spinal muscular atrophy; y, years; m, months; SA, spinal anaesthesia; SMN1, Survival Motor Neuron 1 gene; NAIP, Neuronal Apoptosis Inhibitory Protein; NHLBI, National Heart, Lung, and Blood Institute.