Single nucleotide polymorphisms (SNPs) in the open reading frame (ORF) of prion protein gene (PRNP) in Nigerian livestock species.

BACKGROUND: Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein (PRNP) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases. RESULTS: All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes (n = 54), and the camel had the lowest (n = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all "benign" via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep. CONCLUSION: Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance.

Characterization and genetic diversity of MHC class II DRB genes in the Arabian camel (Camelus dromedarius).

This study investigated the MHC DRB genes in the Arabian camel (Camelus dromedarius). The results revealed the presence of - at least - two transcribed DRB-like genes in chromosome 20, designated MhcCadr-DRB1 and MhcCadr-DRB2. These genes are 155 Kb apart, have similar gene structure, and are transcribed in opposite directions. Compared to DRB1, the DRB2 locus contains a deletion of 12 nucleotides in the second exon (270 bp), exhibits lower transcript abundance, and is expressed as two splice variants differing by exon 2 skipping. This gene seems to be of minor functional relevance in the dromedary camel. Conversely, the DRB1 is thought to be the main gene in this species showing higher transcript abundance and polymorphism levels. A total of seven DRB1 exon 2 alleles were identified in the Tunisian dromedary camel resulting from 18 amino acid substitutions. Six full length alleles were characterized at the mRNA level. Although there is no clear evidence for balancing selection (i.e., heterozygote advantage), signals of weak historical positive selection acting on the DRB1 gene were detected, as indicated by the limited number of the sites being positively selected. This trend might be related to the low exposure to pathogens and to the demographic history of the species. Comparative analysis with Bactrian and wild camel genomes suggested occurrence of trans species polymorphism (TSP) in the Camelus genus. The results lay the foundation for the MHC DRB1 genetic diversity analysis in this genus since the developed genotyping protocols are fully applicable in the three Camelus species.

Factors affecting milk yield and composition of Tunisian camels (Camelus dromedarius) over complete lactation.

This study aimed to investigate the milk production potential and the impact of nongenetic factors on milk yield and composition of Tunisian dromedary camels. Milk recording and sampling were carried out at monthly intervals over complete lactation for 3 years from 95 camels reared in intensive and semi-intensive systems. The overall means of daily milk yield and fat, protein, total solids, and ash contents were 4.21 ± 1.98 l/day, 2.45 ± 0.9%, 2.67 ± 0.74%, 10.75 ± 1.41%, and 0.85 ± 0.08%, respectively. The total milk yield was 1388.41 ± 575.46 l/lactation for 11 months of lactation. The daily milk yield increased regularly throughout lactation until it reached its peak in the 4th month postpartum and then decreased until the 17th month postpartum. The chemical components, except ash, followed an opposite trend to the milk yield. Their minimum contents were recorded during the 7th and 8th months postpartum, while the maximum levels were observed during the 17th month postpartum. Regarding seasonal variation, the highest daily milk yield was recorded during summer (June), whereas the lowest was found in winter (December). In contrast, the maximum and minimum contents of fat and protein were observed during winter (December) and summer (July), respectively. Similarly, total solids content was maximum in January and minimum in August. Parity had no effect on daily milk yield, while all chemical components were higher in milk from primiparous than multiparous camels. Calf sex and management system did not affect the milk yield and composition. These results are useful in order to develop feeding strategies and breeding programs for improving milk production.

Mutations in CAPN1 Cause Autosomal-Recessive Hereditary Spastic Paraplegia.

Hereditary spastic paraplegia (HSP) is a genetically and clinically heterogeneous disease characterized by spasticity and weakness of the lower limbs with or without additional neurological symptoms. Although more than 70 genes and genetic loci have been implicated in HSP, many families remain genetically undiagnosed, suggesting that other genetic causes of HSP are still to be identified. HSP can be inherited in an autosomal-dominant, autosomal-recessive, or X-linked manner. In the current study, we performed whole-exome sequencing to analyze a total of nine affected individuals in three families with autosomal-recessive HSP. Rare homozygous and compound-heterozygous nonsense, missense, frameshift, and splice-site mutations in CAPN1 were identified in all affected individuals, and sequencing in additional family members confirmed the segregation of these mutations with the disease (spastic paraplegia 76 [SPG76]). CAPN1 encodes calpain 1, a protease that is widely present in the CNS. Calpain 1 is involved in synaptic plasticity, synaptic restructuring, and axon maturation and maintenance. Three models of calpain 1 deficiency were further studied. In Caenorhabditis elegans, loss of calpain 1 function resulted in neuronal and axonal dysfunction and degeneration. Similarly, loss-of-function of the Drosophila melanogaster ortholog calpain B caused locomotor defects and axonal anomalies. Knockdown of calpain 1a, a CAPN1 ortholog in Danio rerio, resulted in abnormal branchiomotor neuron migration and disorganized acetylated-tubulin axonal networks in the brain. The identification of mutations in CAPN1 in HSP expands our understanding of the disease causes and potential mechanisms.

Alteration of fatty-acid-metabolizing enzymes affects mitochondrial form and function in hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) is considered one of the most heterogeneous groups of neurological disorders, both clinically and genetically. The disease comprises pure and complex forms that clinically include slowly progressive lower-limb spasticity resulting from degeneration of the corticospinal tract. At least 48 loci accounting for these diseases have been mapped to date, and mutations have been identified in 22 genes, most of which play a role in intracellular trafficking. Here, we identified mutations in two functionally related genes (DDHD1 and CYP2U1) in individuals with autosomal-recessive forms of HSP by using either the classical positional cloning or a combination of whole-genome linkage mapping and next-generation sequencing. Interestingly, three subjects with CYP2U1 mutations presented with a thin corpus callosum, white-matter abnormalities, and/or calcification of the basal ganglia. These genes code for two enzymes involved in fatty-acid metabolism, and we have demonstrated in human cells that the HSP pathophysiology includes alteration of mitochondrial architecture and bioenergetics with increased oxidative stress. Our combined results focus attention on lipid metabolism as a critical HSP pathway with a deleterious impact on mitochondrial bioenergetic function.

[Clinical and environmental aspects of amyotrophic lateral sclerosis in moroccan population: a study of 60 cases]. / Aspects cliniques et environnementaux de la sclérose latérale amyotrophique chez une population morocaine: etude de 60 cas.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is the most common disease of the motor neuron disease. Its etiology remains unknown but several studies incriminate the environmental factors in its genesis. THE AIM: of this study was to describe the epidemiological, clinical and environmental aspects of ALS in Moroccan population. METHODS: 60 ALS patients were recruited over a period of 5 years from January 2008 to September 2012. Patients were evaluated by detailed record of exploitation. Statistical analysis was performed using SPSS 13.0. RESULTS: The average age of the population was 52.1 ± 11.2 years with a sex ratio of M/F = 1.5. The average age of onset was 50 ± 11.7 years. In the group of patients exposed to toxic a significantly higher proportion of solvent exposure was found (p = 0.02). However there was no significant association with exposure to heavy metals, pesticides, or with toxic and eating habits. ALS is more frequent in the west region of Morocco (p = 0.03). CONCLUSIONS: The positive association between exposure to solvents and ALS found in our population has been reported in the literature. The frequency of the ALS early west region suggests may be environmental or genetic origin. These results are preliminary and require a multicenter study to have more data and better highlight the environmental characteristics of ALS in the Moroccan population.

Mathematical model of unemployment with a cyclical component.

In this paper, we proposed and analyzed a new mathematical model of unemployment. Two types of unemployment are involved, structural and cyclical unemployment. The problem is modeled using a nonlinear of ordinary differential system. Three variables are considered, the structural unemployment (S), the employment (E) and the cyclical unemployment (C). Existence, positivity and boundedness of this model are proved. Local stability and global stability are established. The impact of different values of the parameters is analyzed by discussing their sensibility. Numerical simulations are given to confirm the main theoretical findings.

Scrapie-associated polymorphisms of the prion protein gene (PRNP) in Nigerian native goats.

Scrapie is a fatal prion protein disease stiffly associated with single nucleotide polymorphism (SNPs) of the prion protein gene (PRNP). The prevalence of this deadly disease has been reported in small ruminants, including goats. The Nigerian goats are hardy, trypano-tolerant, and contribute to the protein intake of the increasing population. Although scrapie has been reported in Nigerian goats, there is no study on the polymorphism of the PRNP gene. Herein, we evaluated the genetic and allele distributions of PRNP polymorphism in 132 Nigerian goats and compared them with publicly available studies on scrapie-affected goats. We utilized Polyphen-2, PROVEAN and AMYCO programs to examine structural variations produced by the non-synonymous SNPs. Our study revealed 29 SNPs in Nigerian goats, of which 14 were non-synonymous, and 23 were novel. There were significant differences (P < 0.001) in the allele frequencies of PRNP codons 139, 146, 154 and 193 in Nigerian goats compared with scrapie-affected goats, except for Northern Italian goats at codon 154. Based on the prediction by Polyphen-2, R139S and N146S were 'benign', R154H was 'probably damaging', and T193I was 'possibly damaging'. In contrast, PROVEAN predicted 'neutral' for all non-synonymous SNPs, while AMYCO showed a similar amyloid propensity of PRNP for resistant haplotype and two haplotypes of Nigerian goats. Our study is the first to investigate the polymorphism of scrapie-related genes in Nigerian goats.

Polymorphism of prion protein gene (PRNP) in Nigerian sheep.

Polymorphism of the prion protein gene (PRNP) gene determines an animal's susceptibility to scrapie. Three polymorphisms at codons 136, 154, and 171 have been linked to classical scrapie susceptibility, although many variants of PRNP have been reported. However, no study has investigated scrapie susceptibility in Nigerian sheep from the drier agro-climate zones. In this study, we aimed to identify PRNP polymorphism in nucleotide sequences of 126 Nigerian sheep by comparing them with public available studies on scrapie-affected sheep. Further, we deployed Polyphen-2, PROVEAN, and AMYCO analyses to determine the structure changes produced by the non-synonymous SNPs. Nineteen (19) SNPs were found in Nigerian sheep with 14 being non-synonymous. Interestingly, one novel SNP (T718C) was identified. There was a significant difference (P < 0.05) in the allele frequencies of PRNP codon 154 between sheep in Italy and Nigeria. Based on the prediction by Polyphen-2, R154H was probably damaging while H171Q was benign. Contrarily, all SNPs were neutral via PROVEAN analysis while two haplotypes (HYKK and HDKK) had similar amyloid propensity of PRNP with resistance haplotype in Nigerian sheep. Our study provides valuable information that could be possibly adopted in programs targeted at breeding for scrapie resistance in sheep from tropical regions.

An autosomal recessive leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa maps to chromosome 17q24.2-25.3.

BACKGROUND: Single-gene disorders related to ischemic stroke seem to be an important cause of stroke in young patients without known risk factors. To identify new genes responsible of such diseases, we studied a consanguineous Moroccan family with three affected individuals displaying hereditary leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa that appears to segregate in autosomal recessive pattern. METHODS: All family members underwent neurological and radiological examinations. A genome wide search was conducted in this family using the ABI PRISM linkage mapping set version 2.5 from Applied Biosystems. Six candidate genes within the region linked to the disease were screened for mutations by direct sequencing. RESULTS: Evidence of linkage was obtained on chromosome 17q24.2-25.3. Analysis of recombination events and LOD score calculation suggests linkage of the responsible gene in a genetic interval of 11 Mb located between D17S789 and D17S1806 with a maximal multipoint LOD score of 2.90. Sequencing of seven candidate genes in this locus, ATP5H, FDXR, SLC25A19, MCT8, CYGB, KCNJ16 and GRIN2C, identified three missense mutations in the FDXR gene which were also found in a homozygous state in three healthy controls, suggesting that these variants are not disease-causing mutations in the family. CONCLUSION: A novel locus for leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa has been mapped to chromosome 17q24.2-25.3 in a consanguineous Moroccan family.

Genetic Variation in the Prion Protein Gene (PRNP) of Two Tunisian Goat Populations.

Scrapie is a fatal prion disease. It belongs to transmissible spongiform encephalopathies (TSEs), and occurs in sheep and goats. Similarly, to ovine species, the prion protein gene (PRNP) plays a major role in conferring resistance or susceptibility to TSE in goats. This study assesses the variability of PRNP in native and crossed-breed goat populations raised in the Southeast of Tunisia and provides information on the distribution of PRNP haplotypes and genotypes in these goat populations. A total of 116 unrelated goats including 82 native and 34 crossed-breed goats were screened for PRNP polymorphisms using Sanger sequencing. Sequence analysis revealed 10 non-synonymous polymorphisms (G37V, M137I, R139S, I142M, H143R, N146D, R154H, R211Q, Q222K, and S240P), giving rise to 12 haplotypes and 23 genotypes. Moreover, four silent mutations were detected at codons 30, 42, 138, and 179; the former was reported for the first time in goat (nucleotide 60 c→t). Interestingly, the PrP variants associated with resistance (D146 and K222) or with a prolonged incubation time of goat to scrapie (M142, R143, H154, Q211) were absent or detected with low frequencies except for H154 variant, which is present with high frequency (1%, 1%, 4%, 0%, 88%, and 6%, respectively, for native goats, and 0%, 1%, 0%, 1%, 78%, and 1%, respectively, for crossed goats). The analysis of PRNP polymorphisms of goats raised in other regions of the country will be useful in getting a global view of PRNP genetic variability and the feasibility of goat breeding programs in Tunisia.

A locus for bilateral occipital polymicrogyria maps to chromosome 6q16-q22.

We describe the clinical, radiographic, and genetic features of a large consanguineous Moroccan family in which bilateral occipital polymicrogyria segregated as an autosomal recessive trait. Six affected members of the family had partial complex seizures often associated with behavioral abnormalities. On MRI, three patients had a thickened irregular cortex in the lateral occipital lobes with small gyri. A high-density genome-wide scan with 10,000 SNPs established linkage by homozygosity mapping to a 14-Mb region on chromosome 6q16-q22. Candidate genes by function (TUBE1, GRIK2, GPRC6A, GPR6, NR2E1, MICAL1, and MARCKS) in this locus were screened for mutations.

Autosomal recessive axonal Charcot-Marie-Tooth disease (ARCMT2): phenotype-genotype correlations in 13 Moroccan families.

Charcot-Marie-Tooth disease is a genetically heterogeneous group of hereditary motor and sensory neuropathies. Three loci for the axonal autosomal recessive subgroup (ARCMT2) have been reported in 1q21 (CMT2B1, LMNA), 8q21 (CMT4A and CMT2K, GDAP1) and 19q13 (CMT2B2). We report here a clinical, electrophysiological, pathological and genetic study in 13 Moroccan families with ARCMT2 phenotypes. Clinical and electrophysiological examinations were performed in all index cases and 64 'at-risk' relatives. Thirty-one patients were clinically affected. A peroneal nerve biopsy was obtained from three patients. Four families were linked to the 1q21 locus, all had the LMNA R298C mutation. Six families were linked to the 8q21 locus, all had the GDAP1 S194X mutation. Founder effects for both mutations were suggested by the analysis of microsatellite markers close to the genes. The three remaining families were excluded from the three known loci. The electrophysiological findings were consistent with an axonal neuropathy. The clinical data show that in CMT2B1 the disease began most often in the second decade and progressed gradually from distal to proximal muscles. Three of our patients with the longest disease durations (>24 years) had also severe impairment in the scapular muscles. Reported here for the first time, this might be a hallmark of CMT2B1. Patients with CMT4A/2K had onset most often before the age of 2 years. Most had severe clubfoot from the beginning, one of the hallmarks of CMT4A/2K. None of our patients with CMT4A/2K had vocal cord paralysis. The clinical phenotype of the three families that are not linked to the three known loci presented some particularities that were not seen in those with known genetic defects. One family was characterized by late onset of the disease (>20 years) or a mild neuropathy that was diagnosed only when the family was examined. In a second family, dorsal scoliosis was the most prominent symptom. In the third family, symptoms began in the second decade with a moderate neuropathy associated with a pronounced scoliosis. These families illustrate the extent of clinical and genetic heterogeneity in ARCMT2.

Genetic Analysis of Undiagnosed Juvenile GM1-Gangliosidosis by Microarray and Exome Sequencing.

GM1 gangliosidosis is an autosomal recessive lysosomal storage disorder due to mutations in the lysosomal acid 3-galactosidase gene, GLB1. It is usually classified into three forms, infantile, juvenile, or adult, based on age at onset and severity of central nervous system involvement. Because of their broad clinical spectrum and their similarity to many other aetiologies, including inherited neurodegenerative and metabolic diseases, it is often difficult to diagnose such diseases. Recently, whole exome sequencing (WES) has become increasingly used when a strong hypothesis cannot be formulated based on the clinical phenotype. Here, we present three patients belonging to a consanguineous Moroccan family with a GM1-gangliosidosis with unusual clinical onset and atypical radiological presentation that had eluded diagnosis for over a decade. To identify the disease-causing mutation, we performed a whole exome sequencing and a chromosomal microarray genotyping in order to reduce the number of genetic variants to be interpreted, by focusing the data analysis only on the linked loci. The already known pathogenic missense mutation c.601G>A in GLB1 (p.R201C) was found at homozygous state in the proband V.1 and at heterozygous state in his father IV.1. The mutation was validated by Sanger sequencing and segregated in all the family members according to a recessive mode of inheritance. Outside of the linked loci, we found the EXOSC8 p.Ser272Thr mutation at heterozygous state in all the patients and their mother IV.2. This mutation was reported to cause pontocerebellar hypoplasia type 1C and could act as a modifying factor that exacerbates the brain atrophy of patients. Our study identified the first GLB1 mutation in North Africa in patients with unexpected brain-MRI outcomes extending the clinical spectrum of the GM1-gangliosidosis.

Non-Motor Symptoms of Parkinson's Disease and Their Impact on Quality of Life in a Cohort of Moroccan Patients.

BACKGROUND: Non-motor symptoms (NMSs) are a real burden in Parkinson's disease (PD). They may appear in early pre-symptomatic stage as well as throughout the disease course. However, their relationship with the deterioration of the patient's quality of life (QoL) is still under debate. This study aimed to investigate the prevalence of NMSs and their impact on the QoL in a cohort of Moroccan patients. METHODS: We carried out a cross-transactional study, where a total of 117 patients were submitted to a structured clinical interview and examination investigating motor and NMSs based on common and conventional scales. Motor symptoms were assessed by the UPDRS I-VI during ON condition. The NMSs were evaluated with common scales and their relationship with the QoL was investigated. RESULTS: The mean patient's age was 60.77 ± 11.36 years old, and the median disease duration was 6 years [2.5-9.5]. Motor's phenotype subtypes were the mixed form in 40.2% of patients, akinetic-rigid in 20.5% and a tremor-dominant form in 39.3%. The median Hoehn and Yahr staging was 2 [1-2.5]. Regarding NMSs, the most common were urinary dysfunctions (82.6%), sleep (80.6%), and gastrointestinal (80%) disorders. Other autonomic dysfunctions were also frequent: thermoregulatory dysfunctions 58.6%, cardiovascular troubles 50.9%, and sexual dysfunctions 47.9%. Depression was present in 47.9% and fatigue symptoms in 23.1%. The median score of SCOPA-AUT was 14 [7.75-21.80]. The median PD questionnaire 39-score index (PDQ39-SI) was 23.22% and the most affected dimension was "mobility." Univariate and multivariate analyses showed that the SCOPA-AUT score impacted the QoL (p = 0.001), especially the gastrointestinal (p = 0.007), and cardiovascular (p = 0.049) dimensions. CONCLUSION: Our data show that all patients have presented at least one NMS. Autonomic and sleep disorders were the most frequent, and in contrast to other studies, digestive and cardiovascular disorders were rather the factors influencing negatively the QoL of patients. Understanding the pathophysiology of these NMSs should be placed at the forefront in order to develop new therapeutic approaches by improving the QoL of PD patients.

Deep Brain Stimulation in Moroccan Patients With Parkinson's Disease: The Experience of Neurology Department of Rabat.

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known as a therapy of choice of advanced Parkinson's disease. The present study aimed to assess the beneficial and side effects of STN DBS in Moroccan Parkinsonian patients. Material and Methods: Thirty five patients underwent bilateral STN DBS from 2008 to 2016 in the Rabat University Hospital. Patients were assessed preoperatively and followed up for 6 to 12 months using the Unified Parkinson's Disease Rating Scale in four conditions (stimulation OFF and ON and medication OFF and ON), the levodopa-equivalent daily dose (LEDD), dyskinesia and fluctuation scores and PDQ39 scale for quality of life (QOL). Postoperative side effects were also recorded. Results: The mean age at disease onset was 42.31 ± 7.29 years [28-58] and the mean age at surgery was 54.66 ± 8.51 years [34-70]. The median disease duration was 11.95 ± 4.28 years [5-22]. Sixty-three percentage of patients were male. 11.4% of patients were tremor dominant while 45.71 showed akinetic-rigid form and 42.90 were classified as mixed phenotype. The LEDD before surgery was 1200 mg/day [800-1500]. All patients had motor fluctuations whereas non-motor fluctuations were present in 61.80% of cases. STN DBS decreased the LEDD by 51.72%, as the mean LEDD post-surgery was 450 [188-800]. The UPDRS-III was improved by 52.27%, dyskinesia score by 66.70% and motor fluctuations by 50%, whereas QOL improved by 27.12%. Post-operative side effects were hypophonia (2 cases), infection (3 cases), and pneumocephalus (2 cases). Conclusion: Our results showed that STN DBS is an effective treatment in Moroccan Parkinsonian patients leading to a major improvement of the most disabling symptoms (dyskinesia, motor fluctuation) and a better QOL.

A novel GDAP1 mutation P78L responsible for CMT4A disease in three Moroccan families.

BACKGROUND: The gene encoding the ganglioside-induced-differentiation-associated protein 1 (GDAP1) has been associated with both axonal and demyelinating neuropathy. Up to date, 25 mutations in the GDAP1 gene have been reported in patients from different origins. METHODS: Three Moroccan families with early onset ARCMT1 and autosomal recessive inheritance were genotyped to test linkage to 8q21.3 and their GDAP1 gene coding exons screened for mutations. RESULTS: A novel C233T transversion at codon 78 (P78L) was detected in 6 patients from 3 unrelated families. The mutation was found to be homozygous in two families and compound heterozygous in association with the already reported S194X mutation in one family. The P78L mutation was associated with a common haplotype suggesting a Moroccan founder mutation. The patients had symptoms within the two first years of life and developed common phenotype of CMT4A with evident hoarse-voice in two cases with the longer disease duration. CONCLUSION: P78L mutation was associated with a common haplotype suggesting a common ancestor.

Mutation Analysis of Consanguineous Moroccan Patients with Parkinson's Disease Combining Microarray and Gene Panel.

During the last two decades, 15 different genes have been reported to be responsible for the monogenic form of Parkinson's disease (PD), representing a worldwide frequency of 5-10%. Among them, 10 genes have been associated with autosomal recessive PD, with PRKN and PINK1 being the most frequent. In a cohort of 145 unrelated Moroccan PD patients enrolled since 2013, 19 patients were born from a consanguineous marriage, of which 15 were isolated cases and 4 familial. One patient was homozygous for the common LRRK2 G2019S mutation and the 18 others who did not carry this mutation were screened for exon rearrangements in the PRKN gene using Affymetrix Cytoscan HD microarray. Two patients were determined homozygous for PRKN exon-deletions, while another patient presented with compound heterozygous inheritance (3/18, 17%). Two other patients showed a region of homozygosity covering the 1p36.12 locus and were sequenced for the candidate PINK1 gene, which revealed two homozygous point mutations: the known Q456X mutation in exon 7 and a novel L539F variation in exon 8. The 13 remaining patients were subjected to next-generation sequencing (NGS) that targeted a panel of 22 PD-causing genes and overlapping phenotypes. NGS data showed that two unrelated consanguineous patients with juvenile-onset PD (12 and 13 years) carried the same homozygous stop mutation W258X in the ATP13A2 gene, possibly resulting from a founder effect; and one patient with late onset (76 years) carried a novel heterozygous frameshift mutation in SYNJ1. Clinical analysis showed that patients with the ATP13A2 mutation developed juvenile-onset PD with a severe phenotype, whereas patients having either PRKN or PINK1 mutations displayed early-onset PD with a relatively mild phenotype. By identifying pathogenic mutations in 45% (8/18) of our consanguineous Moroccan PD series, we demonstrate that the combination of chromosomal microarray analysis and NGS is a powerful approach to pinpoint the genetic bases of autosomal recessive PD, particularly in countries with a high rate of consanguinity.