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- Khan, Tahir Naeem, et al.
(författare)
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Evidence for autosomal recessive inheritance in SPG3A caused by homozygosity for a novel ATL1 missense mutation
- 2014
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 22:10, s. 1180-1184
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Tidskriftsartikel (refereegranskat)abstract
- Hereditary spastic paraplegias (HSPs) comprise a heterogeneous group of disorders characterized by progressive spasticity and weakness of the lower limbs. Autosomal dominant and 'pure' forms of HSP account for similar to 80% of cases in Western societies of whom 10% carry atlastin-1 (ATL1) gene mutations. We report on a large consanguineous family segregating six members with early onset HSP. The pedigree was compatible with both autosomal dominant and autosomal recessive inheritance. Whole-exome sequencing and segregation analysis revealed a homozygous novel missense variant c.353G>A, p.(Arg118Gln) in ATL1 in all six affected family members. Seven heterozygous carriers, five females and two males, showed no clinical signs of HSP with the exception of sub-clinically reduced vibration sensation in one adult female. Our combined findings show that homozygosity for the ATL1 missense variant remains the only plausible cause of HSP, whereas heterozygous carriers are asymptomatic. This apparent autosomal recessive inheritance adds to the clinical complexity of spastic paraplegia 3A and calls for caution using directed genetic screening in HSP.
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| 2. |
- Klar, Joakim, et al.
(författare)
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Whole exome sequencing identifies LRP1 as a pathogenic gene in autosomal recessive keratosis pilaris atrophicans
- 2015
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Ingår i: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 52:9, s. 599-606
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Tidskriftsartikel (refereegranskat)abstract
- Background Keratosis pilaris atrophicans (KPA) is a group of rare genodermatoses characterised by perifollicular keratosis and inflammation that progresses to atrophy and scars of the facial skin. Keratosis pilaris of extensor areas of limbs is a common associated finding. Most cases with KPA are sporadic and no consistent inheritance pattern has been documented.Methods A large consanguineous Pakistani pedigree segregating autosomal recessive KPA of a mixed type was subject to autozygosity mapping and whole exome sequencing. Quantification of mRNA and protein levels was performed on fibroblasts from affected individuals. Cellular uptake of the low-density lipoprotein (LDL) receptor-related protein 1 (LRP1) ligand alpha 2-macroglobulin (alpha M-2) was quantified using fluorescence confocal microscopy.Results Genetic analyses identified a unique homozygous missense variant (K1245R) in the LRP1 in all affected family members. LRP1 encodes the LRP1, a multifunctional cell surface receptor with endocytic functions that belongs to the LDL receptor family. The LRP1 mRNA and LRP1 protein levels in fibroblasts of affected individuals were markedly reduced when compared with controls. Similarly, the LRP1-mediated cellular uptake of alpha M-2 was reduced in patient fibroblasts. Conclusions This is the first report on LRP1 as a pathogenic gene for autosomal recessive KPA and keratosis pilaris. The inflammatory characteristics of the KPA entity in our family suggest a link to the immune-regulatory functions of LRP1.
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| 3. |
- Nawaz, Sadia, et al.
(författare)
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Report of a recurrent mutation in ARS (component B) gene with severe Mal de Meleda in a large consanguineous Pakistani family
- 2011
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Ingår i: Pakistan journal of medical sciences print. - 1682-024X .- 1681-715X. ; 27:3, s. 686-689
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To characterize the disease causing mutation in a large consanguineous Pakistani family with severe Mat de Meleda (MDM) or keratosis palmoplantaris transgrediens, a rare autosomal recessive skin disorder. Methodology: Single nucleotide polymorphism (SNPs) genotyping was performed using the Gene Chip Mapping 250K array (Affymetrix). Homozygosity mapping and sorting of genomic regions were performed with dedicated software called AutoSNPa. Selected regions were further investigated by genotyping with microsatellite markers derived from known and novel pOlymorphic repeats. Two-point LOD score calculation was performed by using the MLINK of Fast link computer package. All three coding exons of ARS (component B) gene were amplified by PCR and sequenced. Conclusion: Sequencing of all the coding exons of ARS (component B) gene in the affected individuals revealed a recurrent missense mutation in exon 3 at base pair 256 from Guanine to Alanine (256G>A) and as a result the amino acid Glycine is replaced by Arginine at position 86 (G86R). This finding will facilitate control of affected MDM births in the Pakistani families.
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