A newborn Screening Programme for Inborn errors of metabolism in Galicia: 22 years of evaluation and follow-up.

BACKGROUND: There is a notable lack of harmonisation in newborn screening (NBS) programmes worldwide. The Galician programme for early detection of inborn errors of metabolism (IEM) was one of the first NBS programmes in Europe to incorporate mass spectrometry (July 2000). This programme currently screens for 26 IEMs in dried blood and urine samples collected 24-72 h after birth. RESULTS: In its 22-year history, this programme has analysed samples from 440,723 neonates and identified 326 cases of IEM with a prevalence of 1:1351. The most prevalent IEMs were hyperphenylalaninaemia (n = 118), followed by medium chain acyl-CoA dehydrogenase deficiency (MCADD, n = 26), galactosaemia (n = 20), and cystinurias (n = 43). Sixty-one false positives and 18 conditions related to maternal pathologies were detected. Urine samples have been identified as a useful secondary sample to reduce the rate of false positives and identify new defects. There were 5 false negatives. The overall positive value was 84.23%. The fatality rate over a median of 12.1 years of follow-up was 2.76%. The intelligence quotient of patients was normal in 95.7% of cases, and school performance was largely optimal, with pedagogic special needs assistance required in < 10% of cases. Clinical onset of disease preceded diagnosis in 4% of cases. The age at which first NBS report is performed was reduced by 4 days since 2021. CONCLUSIONS: This study highlights the benefits of collecting urine samples, reduce NBS reporting time and expanding the number of IEMs included in NBS programmes.

Maturity-onset diabetes of the young in a large Portuguese cohort.

AIMS: Monogenic forms of diabetes that develop with autosomal dominant inheritance are classically aggregated in the Maturity-Onset Diabetes of the Young (MODY) categories. Despite increasing awareness, its true prevalence remains largely underestimated. We describe a Portuguese cohort of individuals with suspected monogenic diabetes who were genetically evaluated for MODY-causing genes. METHODS: This single-center retrospective cohort study enrolled patients with positive genetic testing for MODY between 2015 and 2021. Automatic sequencing and, in case of initial negative results, next-generation sequencing were performed. Their clinical and molecular characteristics were described. RESULTS: Eighty individuals were included, 55 with likely pathogenic/pathogenic variants in one of the MODY genes and 25 MODY-positive family members, identified by cascade genetic testing. The median age at diabetes diagnosis was 23 years, with a median HbA1c of 6.5%. The most frequently mutated genes were identified in HNF1A (40%), GCK (34%) and HNF4A (13%), followed by PDX1, HNF1B, INS, KCNJ11 and APPL1. Thirty-six unique variants were found (29 missense and 7 frameshift variants), of which ten (28%) were novel. CONCLUSIONS: Our data highlights the importance of genetic testing in the diagnosis of MODY and the establishment of its subtypes, leading to more personalized treatment and follow-up strategies.

Rapid Molecular Diagnosis of Genetically Inherited Neuromuscular Disorders Using Next-Generation Sequencing Technologies.

Neuromuscular diseases are genetically highly heterogeneous, and differential diagnosis can be challenging. Over a 3-year period, we prospectively analyzed 268 pediatric and adult patients with a suspected diagnosis of inherited neuromuscular disorder (INMD) using comprehensive gene-panel analysis and next-generation sequencing. The rate of diagnosis increased exponentially with the addition of genes to successive versions of the INMD panel, from 31% for the first iteration (278 genes) to 40% for the last (324 genes). The global mean diagnostic rate was 36% (97/268 patients), with a diagnostic turnaround time of 4-6 weeks. Most diagnoses corresponded to muscular dystrophies/myopathies (68.37%) and peripheral nerve diseases (22.45%). The most common causative genes, TTN, RYR1, and ANO5, accounted for almost 30% of the diagnosed cases. Finally, we evaluated the utility of the differential diagnosis tool Phenomizer, which established a correlation between the phenotype and molecular findings in 21% of the diagnosed patients. In summary, comprehensive gene-panel analysis of all genes implicated in neuromuscular diseases facilitates a rapid diagnosis and provides a high diagnostic yield.

Oleate Prevents Palmitate-Induced Mitochondrial Dysfunction in Chondrocytes.

The association between obesity and osteoarthritis (OA) in joints not subjected to mechanical overload, together with the relationship between OA and metabolic syndrome, suggests that there are systemic factors related to metabolic disorders that are involved in the metabolic phenotype of OA. The aim of this work is study the effects of palmitate and oleate on cellular metabolism in an "in vitro" model of human chondrocytes. The TC28a2 chondrocyte cell line was used to analyze the effect of palmitate and oleate on mitochondrial and glycolytic function, Adenosine triphosphate (ATP) production and lipid droplets accumulation. Palmitate, but not oleate, produces mitochondrial dysfunction observed with a lower coupling efficiency, maximal respiration and spare respiratory capacity. Glycolytic function showed lower rates both glycolytic capacity and glycolytic reserve when cells were incubated with fatty acids (FAs). The production rate of total and mitochondrial ATP showed lower values in chondrocytes incubated with palmitic acid (PA). The formation of lipid droplets increased in FA conditions, being significantly higher when the cells were incubated with oleic acid (OL). These results may help explain, at least in part, the close relationship of metabolic pathologies with OA, as well as help to elucidate some of the factors that can define a metabolic phenotype in OA.