Relative Frequency of Metachromatic Leukodystrophy in Egypt: A Reference Laboratory Report.

Background: Metachromatic leukodystrophy (MLD) is an autosomal recessive hereditary neurodegenerative disease caused by a deficiency in arylsulfatase A (ARSA) activity and belongs to the group of lysosomal storage diseases. A biochemical diagnosis of MLD is based on determining the residual ARSA activity in leukocytes, skin fibroblasts, and urine. This study documents our biochemical experience and estimates the relative frequency of MLD over 21 years (2001-2022).

Novel gene-specific Bayesian Gaussian mixture model to predict the missense variants pathogenicity of Sanfilippo syndrome.

MPS III is an autosomal recessive lysosomal storage disease caused mainly by missense variants in the NAGLU, GNS, HGSNAT, and SGSH genes. The pathogenicity interpretation of missense variants is still challenging. We aimed to develop unsupervised clustering-based pathogenicity predictor scores using extracted features from eight in silico predictors to predict the impact of novel missense variants of Sanfilippo syndrome.

Biochemical diagnosis of Sanfilippo disorder types A and B.

Background: One of the 11 recognized mucopolysaccharidosis (MPS) diseases is Sanfilippo. It is autosomal recessive in its mode of transmission. There are four subtypes of Sanfilippo (A, B, C, and D).

Profile of plasma free amino acids, carnitine and acylcarnitines, and JAK2 mutation as potential metabolic markers in children with type 1 diabetic nephropathy.

Fifty diabetic nephropathy (DN) children with type 1 diabetes mellitus (T1DM) and 50 healthy matched controls were included. Chromatographic assays of 14 amino acids, free carnitine and 27 carnitine esters using high-performance liquid chromatography/electrospray ionization-mass spectroscopy, and genetic testing for JAK2 mutation using real-time PCR were performed. Patients had significantly lower levels of tyrosine, branched-chain amino acids (BCAAs), and BCAA/AAA (aromatic chain amino acids) ratios, glycine, arginine, ornithine, free carnitine and some carnitine esters (C5, 6, 12 and 16) and higher phenylalanine, phenylalanine/tyrosine ratio and C18 compared with the controls and in the macro-albuminuria vs.

Biochemical and mutational analyses of HEXA in a cohort of Egyptian patients with infantile Tay-Sachs disease. Expansion of the mutation spectrum.

Background: Tay-Sachs disease (TSD), an autosomal recessively inherited neurodegenerative lysosomal storage disease, reported worldwide with a high incidence among population of Eastern European and Ashkenazi Jewish descent. Mutations in the alpha subunit of HEXA that encodes for the β-hexosaminidase-A lead to deficient enzyme activity and TSD phenotype. This study is the first to highlight the HEXA sequence variations spectrum in a cohort of Egyptian patients with infantile TSD.