Prenatal diagnosis of pyruvate dehydrogenase E1-α deficiency: a case report / 中华围产医学杂志

This article reported a case of pyruvate dehydrogenase E1-α deficiency suggested by abnormal brain development during prenatal ultrasound imaging. Prenatal ultrasound revealed a mild enlargement of bilateral cerebral ventricles and the possibility of intracranial hemorrhage in the fetus at 25 +1 weeks of gestation. MRI showed the fetus with absent corpus callosum, enlarged bilateral cerebral ventricles and paraventricular cysts. After genetic counseling and careful consideration, the couple opted for pregnancy termination. To clarify the cause of the disease, whole-exome sequencing was performed on the fetal skin to detect possible variants, and which revealed a frameshift mutation c.924_930dup(p.R311Gfs*5) in exon 10 of the PDHA1 gene. Sanger sequencing confirmed the mutation was a de novo pathogenic variant, indicating that the fetus was affected by pyruvate dehydrogenase E1-α deficiency.

Transport of Lipoamide and Lipoic Acid in Caco-2 Cell Monolayer Model / 中国药学杂志

OBJECTIVE: To study the transport of lipoamide (LAM) and lipoic acid (LA) in Caco-2 cell monolayer model in vitro. METHODS: Effects of LAM and LA on the survival rate of Caco-2 cells were investigated by MTS, the bi-directional transport of lipoamide and lipoic acid from the intestinal cavity side (apical side, AP) to the basal side (basolateral side,BL) was investigated. The cumulative transport volume, apparent permeability coefficient (Papp) and transport percentage were calculated,and the relationships between transport volume and concentration and time were further studied. RESULTS: The transport amounts of LAM and LA were increased in time-and concentration-dependent manners, the Papps of LAM and LA (AP→BL) were 2.443 44×10-5-2.392 91×10-5 and 8.179 78×10-6-7.897 25×10-6 cm•s-1, and the Papps(BL→AP) were 2.258 13×10-5-2.214 3×10-5 and 8.267 98×10-6-7.926 73×10-6 cm•s-1, respectively. CONCLUSION: In the transport test of Caco-2 cells, LAM is superior to LA, suggesting that it is well absorbed orally and has high bioavailability. But it is still necessary to verify the pharmacokinetic data in vivo.

Gene mutations and prenatal diagnosis in families with maple syrup urine disease / 中华围产医学杂志

Objective Maple syrup urine disease (MSUD) is a rare metabolic disorder caused by deficiency of the activity of branched-chain 2-keto acid dehydrogenase complex.The complex contains E1α,E1β and E2 subunits which are encoded by BCKDHA,BCKDHB or DBT genes respectively.Mutation in any gene will cause MSUD.The aim of this study was to analyze the gene mutations of four cases with MSUD and carry out prenatal diagnosis for these four families for MSUD.Methods From 2005 to 2010,four neonates (two males and two females) were diagnosed as MSUD at 2,5,10and 26 days of life.The coding regions of BCKDHA gene and BCKDHB gene in the above four cases were amplified by polymerase chain reaction and analyzed by direct DNA sequencing.During the second pregnancy of the same mother,the amniotic fluid was drawn out at 16-20 weeks for gene mutation analysis after the amniocytes were cultured.Results Mutation analysis revealed six mutations in four patients,including four novel mutations (c.308T＞C,c.562G＞T,c.1279C＞G and c.1280-1291de112) and two previously reported mutations.Five mutations (c.308T＞C,c.562G ＞T,c.868G＞A,c.1279C＞G and c.1280-1291de112) were detected on BCKDHA gene in three patients.While one mutation (c.853C＞T) was found on BCKDHB gene in one patient.Only one mutation was found in the amniocytes of each patient's mother at their second pregnancies suggesting a MSUD heterozygous fetus.Conclusions Analysis of BCKDHA and BCKDHB allowed preliminary understand of gene mutations in the four MSUD families,and made prenatal diagnosis possible,which helped in consultation in the second pregnancy.

A Korean Female Patient with Thiamine-responsive Pyruvate Dehydrogenase Complex Deficiency Due to a Novel Point Mutation (Y161C)in the PDHA1 Gene

Pyruvate dehydrogenase complex (PDHC) deficiency is mostly due to mutations in the X-linked E1alpha subunit gene (PDHA1). Some of the patients with PDHC deficiency showed clinical improvements with thiamine treatment. We report the results of biochemical and molecular analysis in a female patient with lactic acidemia. The PDHC activity was assayed at different concentrations of thiamine pyrophosphate (TPP). The PDHC activity showed null activity at low TPP concentration (1 x 10(-3) mM), but significantly increased at a high TPP concentration (1 mM). Sequencing analysis of PDHA1 gene of the patient revealed a substitution of cysteine for tyrosine at position 161 (Y161C). Thiamine treatment resulted in reduction of the patient's serum lactate concentration and dramatic clinical improvement. Biochemical, molecular, and clinical data suggest that this patient has a thiamine-responsive PDHC deficiency due to a novel mutation, Y161C. Therefore, to detect the thiamine responsiveness it is necessary to measure activities of PDHC not only at high but also at low concentration of TPP.