Explore the vast range of titles available.

Pennsylvania started newborn screening for Pompe disease in February 2016. Between February 2016 and December 2019, 531,139 newborns were screened. Alpha-Glucosidase (GAA) enzyme activity is measured by flow-injection tandem mass spectrometry (FIA/MS/MS) and full sequencing of the GAA gene is performed as a second-tier test in all newborns with low GAA enzyme activity [<2.10 micromole/L/h]. A total of 115 newborns had low GAA enzyme activity and abnormal genetic testing and were referred to metabolic centers. Two newborns were diagnosed with Infantile Onset Pompe Disease (IOPD), and 31 newborns were confirmed to have Late Onset Pompe Disease (LOPD). The incidence of IOPD + LOPD was 1:16,095. A total of 30 patients were compound heterozygous for one pathogenic and one variant of unknown significance (VUS) mutation or two VUS mutations and were defined as suspected LOPD. The incidence of IOPD + LOPD + suspected LOPD was 1: 8431 in PA. We also found 35 carriers, 15 pseudodeficiency carriers, and 2 false positive newborns.

Dihydrolipoamide dehydrogenase (DLD; E3) oxidizes lipoic acid. Restoring the oxidized state allows lipoic acid to act as a necessary electron sink for the four mitochondrial keto‐acid dehydrogenases: pyruvate dehydrogenase, alpha‐ketoglutarate dehydrogenase, branched‐chain α‐keto‐acid dehydrogenase, and 2‐oxoadipate dehydrogenase. DLD deficiency (DLDD) is caused by biallelic pathogenic variants in DLD . Three major forms have been described: encephalopathic, hepatic, and myopathic, although DLDD patients exhibit overlapping phenotypes. Hyperlactatemia, hyperexcretion of tricarboxylic acid cycle (TCA) metabolites and branched‐chain keto acids, increased plasma branched‐chain amino acids and allo‐isoleucine are intermittent metabolic abnormalities reported in patients with DLDD. However, the diagnostic performance of these metabolites has never been studied. Therefore, we sought to systematically evaluate the diagnostic utility of these biomarkers for DLDD. We retrospectively analyzed the results of biochemical testing of six unrelated DLDD patients, including values obtained during both well visits and acute decompensation episodes. Elevation of branched‐chain amino acid concentrations was not consistently observed. We found that five of six patients in our cohort had a maximum lifetime value of allo‐isoleucine of 6 μmol/L, showing that alloisoleucine elevations even during illness may be subtle. Urine organic acid analysis (UOA) during acute decompensation episodes was abnormal in all cases; however, the pattern of abnormalities had high intersubject variability. No single biomarker was universally present, even in patients experiencing metabolic decompensation. We also observed novel biochemical associations: three patients had hyperexcretion of TCA cycle metabolites during crisis; in two patients, 2‐ketoadipic and 2‐hydroxyadipic acids, by products of lysine degradation, were detected. We propose that these result from 2‐oxoadipate dehydrogenase deficiency, an underappreciated biochemical abnormality in DLD. Given the diversity of biochemical profiles among the patients with DLDD, we conclude that accurate biochemical diagnosis relies on a high index of suspicion and multipronged biochemical analysis, including both plasma amino acid and urine organic acid quantitation during decompensation. Biochemical diagnosis during the well state is challenging. We emphasize the critical importance of multiple simultaneous biochemical tests for diagnosis and monitoring of DLDD. We also highlight the under‐recognized role of DLD in the lysine degradation pathway. Larger cohorts of patients are needed to establish a correlation between the biochemical pattern and clinical outcomes, as well as a genotype–phenotype correlation.

Type II D‐2‐Hydroxyglutaric aciduria (T2D2HGA) is caused by a gain‐of‐function pathogenic variant in Isocitrate Dehydrogenase 2 (IDH2). Patients with T2D2HGA commonly present with developmental delay, seizures, cardiomyopathy, and arrhythmias. The recently approved IDH2‐inhibitor Enasidenib targets the p.Arg140Gln pathogenic IDH2 variant and decreases production of D2HGA. We present a 7‐year‐old female with T2D2HGA due to the p.Arg140Gln variant. She was diagnosed at 3‐years‐old after presenting with global developmental delay, leukoencephalopathy, communicating hydrocephalus, seizures, and dilated cardiomyopathy. At age 3 years 11 months, 50 mg Enasidenib daily was initiated. Primary outcomes included seizure frequency, hospital admissions, development, and cardiac structure. Laboratories were monitored biweekly for common Enasidenib side effects. Our patient tolerated Enasidenib well. Urine 2‐HGA decreased significantly from 244 mg/g creatinine to undetectable within 2 weeks of treatment. Inpatient admissions decreased from 8 during the 2 years preceding treatment to 1 during treatment. She has been seizure‐free since Enasidenib initiation. Echocardiography showed improvement in dilated cardiomyopathy with normal left ventricular systolic function. Developmental assessment demonstrated improvements in gross motor, fine motor, language, and socialization domains. Treatment was complicated by mild elevations in alanine transaminase (118 IU/L, range 0–28) and creatine kinase (334 U/L, range 45–198) that resolved by decreasing Enasidenib dosing frequency to three times weekly. Enasidenib is a viable treatment for Type II D2HGA with benefits including developmental gains, fewer acute medical interventions, and cardiomyopathy improvement. While drug‐induced hepatitis is a novel adverse effect of Enasidenib, it can be ameliorated by decreasing dose frequency.

Pennsylvania started newborn screening for Pompe disease (PD) in 2016. As a result, the prevalence of PD has increased with early detection, primarily of late-onset Pompe disease (LOPD). No clear guidelines exist regarding if and when to initiate enzyme replacement therapy (ERT) in patients identified through a newborn screen (NBS). To help define the natural history and indications for starting ERT, we present the long-term follow-up data of 45 patients identified through NBS from 2016 to 2021. These patients were evaluated at regular intervals through our multi-disciplinary clinic at the Children’s Hospital of Philadelphia (CHOP) with physical examinations, physical therapy evaluations, muscle biomarkers including creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hexosaminidase 4 levels (Hex4), as well as cardiac evaluation at certain points in time. We found that newborn screening of acid alpha-glucosidase (GAA) enzyme detected primarily LOPD. One case of infantile-onset PD (IOPD) was detected. Muscle biomarkers in LOPD were elevated at birth and showed a general downward trend over time. NBS GAA levels and initial CK levels helped to differentiate LOPD cases from unaffected infants (carriers, pseudodeficiency alleles), while Hex4 was not a meaningful discriminator. On repeat NBS, there was a significant difference between mean GAA levels for the unaffected vs. compound heterozygote groups and unaffected vs. homozygote groups for the common splice site pathogenic variant (c.-32-13T>G). Echocardiogram and electrocardiogram (EKG) are essentially normal at the first evaluation in LOPD. One LOPD patient was started on ERT at age 4.5 months. Continued data collection on these patients is critical for developing management guidelines, including timing of ERT and improved genotype–phenotype correlation.

In a retrospective review of patients seen at the University of Alabama at Birmingham Cleft and Craniofacial Center, four patients with rare interrupted clefting were identified who had undergone genetic testing. Each of these patients had a typical cleft lip, with intact hard palate and cleft of the soft palate. Given this picture of mixed clefting, IRF6 sequencing was done and was negative for mutations in all four patients. As genetic testing for single-gene mutations and exome sequencing become clinically available, it may be possible to identify novel mutations responsible for this previously unreported type of interrupted clefting.

Purpose: Despite implementation of newborn screening (NBS), outcomes in cobalamin C disease (cblC) remain poor. Therapy with hydroxycobalamin and betaine is widely used, but dietary recommendations vary among metabolic centers. We present a longitudinal analysis of the relationship between metabolic control, diet, and outcomes in a cohort of cblC patients. Methods: We completed a retrospective analysis of 12 patients with cblC referred for abnormal NBS results and followed in our center between 1999 and 2015. Results: Of the patients, 87.5% had intellectual disability and 75% had retinopathy; 16.7% had one episode of mild acidosis. However, no patients manifested major metabolic decompensation. Developmental outcomes correlated more closely with initial metabolic abnormalities than with long-term metabolic control. Increased intake of medical foods resulted in better control but also perturbations in the ratios of essential amino acids and lower z -scores for head circumference. We found no relationship between diet and cognitive outcomes. Conclusions: Although dietary therapy for cblC patients improves metabolic control, few patients experience metabolic decompensation regardless of diet. Increased incomplete protein intake is not correlated with improvements in outcomes. Overall, outcomes are poor despite early initiation of therapy and regardless of the dietary strategy used. Genet Med advance online publication 02 February 2017