Spectrum of Organic Aciduria Diseases in Tunisia: A 35-year Retrospective Study.

Background: Organic aciduria diseases (OADs) occur worldwide, with differences in prevalence and patterns between populations.

Objectives: To describe the spectrum of OADs identified in Tunisia over a 35-years period.

Materials And Methods: This retrospective study included patients who were diagnosed with OADs between 1987 and 2022 in the Laboratory of Biochemistry, Rabta Hospital, Tunisia.

Analysis of Branched Amino Acids by UPLC as an Alternative Method for the Management of Patients with MUSD.

Background: Maple syrup urine disease (MSUD) is a severe life-threatening metabolic disorder. Patients' poor outcomes could be prevented by early diagnosis and regular monitoring, which mainly depend on the analysis of branched amino acids (BCAAs) in plasma. The study aimed to test whether the analysis of BCAAs by ultra-performance liquid chromatography (UPLC) is an alternative to an analysis by ion-exchange chromatography (IEC) for the diagnosis and monitoring of MSUD.

Incidence of the Mucopolysaccharidoses in Tunisia, 1999 - 2021.

Background: This cross-sectional study aimed to describe and discuss the epidemiology of mucopolysaccharidoses (MPS) in Tunisia.

Methods: Patients diagnosed with a MPS disorder in two referral laboratories in Tunisia between 1999 and 2021 were included. Diagnosis was based on clinical and radiological features and analysis of urinary glycosaminoglycans, and enzyme assay in some of the patients.

Semen Creatine and Creatine Kinase Activity as an Indicator of Sperm Quality.

Background: The role of creatine (Cr) and creatine kinase (CK) in sperm function remains unclear. The study aimed to assess Cr and CK in seminal plasma and test their association with sperm characteristics.

Methods: The study included 62 males with couple's infertility and 26 males who have already fathered children.

Nonketotic Hyperglycinemia in Tunisia. Report upon a Series of 69 Patients.

Aim: The aim of the study is to report on epidemiological, clinical, and biochemical characteristics of nonketotic hyperglycinemia (NKH) in Tunisia.

Methods: Patients diagnosed with NKH in Laboratory of Biochemistry at Rabta hospital (Tunis, Tunisia) between 1999 and 2018 were included. Plasma and cerebrospinal fluid (CSF) free amino acids were assessed by ion exchange chromatography.

Biochemical and clinical profiles of 52 Tunisian patients affected by Zellweger syndrome.

Background: Zellweger syndrome (ZS) is a peroxisome biogenesis disorder attributed to a mutation of the PEX genes family. The incidence of this disease in Africa and the Arab world remains unknown. This contribution is aimed at describing the clinical phenotype and biochemical features in Tunisian patients with ZS in order to improve the detection and management of this severe disorder.

X-linked Adrenoleukodystrophy, The Tunisian Experience.

Background: X-linked adrenoleukodystrophy is a genetic disease affecting the degradation of very long chain fatty acids. This study aims to describe the clinical phenotype and biochemical feature of Tunisian patients; it also seeks to describe recognition of pattern analysis on the level of very long chain fatty acids in plasma for the visual discrimination of X-linked patients from a healthy group.

Methods: During the last 21 years, 19 patients were diagnosed with X-linked adrenoleukodystrophy based on the clinical features combined with the area percentage of hexacosanoic acid (C26:0) as well as the ratio of C26:0 and lignoceric acid (C24:0) relative to behenic acid (C22:0) by gas chromatography.

Clinical and Biochemical Profile of Tyrosinemia Type 1 in Tunisia.

Background: Hereditary tyrosinemia type 1 (HT1) is an autosomal recessive disease caused by a defect of fumarylacetoacetate hydrolase. This study aimed to estimate the prevalence of HT1 in Tunisia and report its clinical, biochemical and genetic features.

Methods: During the last 25 years, 69 patients were diagnosed with HT1 based on clinical features and increased succinylacetone (SA) in blood and urine.

Guanidinoacetate methyltransferase (GAMT) deficiency in two Tunisian siblings: clinical and biochemical features.

Background: Guanidinoacetate methyltransferase (GAMT) deficiency is a recently described disorder and few cases have been reported to date. As it is a treatable pathology, we seek to contribute to its better understanding, particularly to further elucidate its biochemical diagnosis for early treatment.

Methods: The patients, two brothers aged 13 years (P1) and 11 years (P2), have been explored for signs and symptoms suggestive of inborn errors of metabolism.

GC/MS determination of guanidinoacetate and creatine in urine: A routine method for creatine deficiency syndrome diagnosis.

Objectives: To further facilitate the diagnosis of creatine deficiency syndromes (CDS) a modified method was developed for the quantification of urinary creatine and guanidinoacetoacetate using gas chromatography/mass spectrometry (GC/MS) and having the additional advantage of using the same derivatizing agents, column and equipment usually used for the diagnosis of the organic acidurias in the clinical biochemistry laboratories.

Material And Methods: Guanidinoacetic acid, creatine standard solutions and pooled urines and pathological samples were used to validate a new and simple GC/MS technique modified from reported methods; its accuracy was assessed by comparing with liquid chromatography-electrospray tandem mass spectrometry (HPLC-MS/MS) method.

Results: The method is precise: intra assay and inter assay variability for low and high concentrations were 3%, 6.

Creatine and creatine deficiency syndromes: biochemical and clinical aspects.

Creatine deficiency syndromes, which have only recently been described, represent a group of inborn errors of creatine synthesis (L-arginine-glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency) and transport (creatine transporter deficiency). Patients with creatine deficiency syndromes present with mental retardation expressive speech and language delay, and epilepsy. Patients with guanidinoacetate methyltransferase deficiency or creatine transporter deficiency may exhibit autistic behavior.