Pancreatic involvement in patients with inborn errors of metabolism.

BACKGROUND: Repeated inflammation of the pancreas can cause pancreatitis or diabetes. It is well recognized that the organic acidemias may be complicated by pancreatitis but less recognized are other metabolic disorders in which pancreatitis can occur. This study shows that long-term follow-up of patients with various metabolic disorders in Korea revealed several with episodes of isolated pancreatitis or diabetes concomitantly with pancreatitis. RESULTS AND DISCUSSION: In this study, two patients with methylmalonic aciduria (MMA), two with propionic acidemia (PPA), one with fatty acid oxidation disorder (FAOD), and one with hyperornithinemia, gyrate atrophy, and juvenile onset diabetes mellitus (DM) were clinically followed for up to 10 - 21 years. Two Korean siblings with MMA showed recurrent pancreatitis from the age of 15 and 19, respectively. The frequency of admission due to pancreatitis was up to 11 times. One patient with MMA developed diabetes mellitus at the age of 20. The other patient with MMA developed recurrent pancreatitis at 4 years and diabetes at 8 years of age. One of the patients with PPA presented with diabetic ketoacidosis. The other PPA patient died of cardiac arrest at age 10. The patient with FAOD presented with pancreatitis at 10 years and died at the age of 15 years due to cardiac arrest. A 35-year-old woman with hyperornithinemia/gyrate atrophy was diagnosed with juvenile onset diabetes at the age of 7 years. No pancreatitis occurred during the follow-up period. CONCLUSIONS: We conclude that various metabolic disorders can trigger acute or chronic pancreatitis. Proper and prompt multidisciplinary management of metabolic derangement is crucial for preventing pancreatic damage. Further clinical and investigational studies are required to elucidate the pathogenesis of pancreatitis and diabetes mellitus in patients with inborn errors in metabolism.

Characteristic dysmorphic features in congenital disorders of glycosylation type IIb.

Over 100 types of congenital disorders of glycosylation (CDG) have been reported and the number is rapidly increasing. However, each type is very rare and is problematic to diagnose. Mannosyl-oligosaccharide glucosidase (MOGS)-CDG (CDG type IIb) is an extremely rare CDG that has only been reported in three patients from two unrelated families. Using targeted exome sequencing, we identified another patient affected by this condition. This patient had increased serum trisialotransferrin levels. Importantly, a review of the features of all four patients revealed the recognizable clinical hallmarks of MOGS-CDG. The distinct dysmorphic features of this condition include long eyelashes, retrognathia, hirsutism, clenched overlapped fingers, hypoventilation, hepatomegaly, generalized edema, and immunodeficiency.

Further delineation of COG8-CDG: A case with novel compound heterozygous mutations diagnosed by targeted exome sequencing.

Congenital disorders of glycosylation (CDG) are a rapidly expanding group of inherited metabolic disorders with highly variable clinical presentations caused by deficient glycosylation of proteins and/or lipids. CDG-IIh is a very rare subgroup of CDG caused by mutations in the conserved oligomeric Golgi (COG) complex gene, COG8, and so far, only two cases have been reported in the medical literature. Here, we describe an 8-year-old Korean boy with psychomotor retardation, hypotonia, failure to thrive, elevated serum liver enzymes, microcephaly, and talipes equinovarus. A liver biopsy of the patient showed only interface hepatitis with mild lobular activity, and brain magnetic resonance imaging revealed cerebellar atrophy. Compared with the previous two reported cases, our patient showed relatively mild psychomotor retardation without a seizure history. The transferrin isoelectric focusing profiles in the patient showed a CDG type II pattern with increased disialo- and trisialo-transferrin. Targeted exome sequencing was performed to screen all CDG type II-related genes, and two novel frameshift mutations were found: c.171dupG (p.Leu58Alafs*29) and c.1656dupC (p.Ala553Argfs*15) in COG8. The parents were heterozygous carriers of each variant. CDG should be included in the initial differential diagnosis for children with a suspected unknown syndrome or unclassified inherited metabolic disorder or children with diverse clinical presentations, such as psychomotor retardation, hypotonia, skeletal deformity, microcephaly, cerebellar atrophy, and unexplained transient elevated liver enzyme.

Targeted population screening of late onset Pompe disease in unspecified myopathy patients for Korean population.

We performed targeted population screening of late onset Pompe disease (LOPD) in unspecified myopathy patients, because early diagnosis is difficult due to its heterogeneous clinical features. We prospectively enrolled 90 unrelated myopathic patients who had one or more signs out of five LOPD-like clinical findings (proximal weakness, axial weakness, lingual weakness, respiratory difficulty, idiopathic hyperCKemia). Acid alpha glucosidase activity was evaluated with dried blood spot and mixed leukocyte simultaneously. For a final diagnosis of LOPD, 16 patients with decreased enzyme activity were genotyped by GAA molecular analysis. We found two patients with LOPD (2.2%), and the remaining 14 patients had at least one G576S or E689K mutation, known as the pseudodeficiency allele. Acid alpha glucosidase activity of LOPD patients was significantly lower than that of patients with at least one pseudodeficiency allele (p = 0.017). This study is the first LOPD screening study for targeted Korean population, and more generally, an Asian population. Our findings suggest that for diagnosis of LOPD in Asian population, modified cutoff value of acid alpha glucosidase activity with dry blood spot considering that of patients having heterozygote pathogenic variants or pseudodeficiency alleles may reduce time and cost requirements and increase the comfort of patients.

Compound heterozygous mutations of ACADS gene in newborn with short chain acyl-CoA dehydrogenase deficiency: case report and literatures review.

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is a rare autosomal recessive mitochondrial disorder of fatty acid ß-oxidation, and is associated with mutations in the acyl-CoA dehydrogenase (ACADS) gene. Recent advances in spectrometric screening for inborn errors of metabolism have helped detect several metabolic disorders, including SCADD, without symptoms in the neonate period. This allows immediate initiation of treatment and monitoring, so they remain largely symptomless metabolic disease. Here, we report a 15-month-old asymptomatic male, who was diagnosed with SCADD by newborn screening. Spectrometric screening for inborn errors of metabolism 72 hours after birth revealed an elevated butyrylcarnitine (C4) concentration of 2.25 µmol/L (normal, <0.99 µmol/L). Urinary excretion of ethylmalonic acid was also elevated, as detected by urine organic acid analysis. To confirm the diagnosis of SCADD, direct sequencing analysis of 10 coding exons and the exon-intron boundaries of the ACADS gene were performed. Subsequent sequence analysis revealed compound heterozygous missense mutations c.164C>T (p.Pro55Leu) and c.1031A>G (p.Glu344Gly) on exons 2 and 9, respectively. The patient is now growing up, unretarded by symptoms such as seizure and developmental delay.