Characterization of Mutations Causing CYP21A2 Deficiency in Brazilian and Portuguese Populations

Deficiency of 21-hydroxylase enzyme (CYP21A2) represents 90% of cases in congenital adrenal hyperplasia (CAH), an autosomal recessive disease caused by defects in cortisol biosynthesis. Computational prediction and functional studies are often the only way to classify variants to understand the links to disease-causing effects. Here we investigated the pathogenicity of uncharacterized variants in the CYP21A2 gene reported in Brazilian and Portuguese populations. Physicochemical alterations, residue conservation, and effect on protein structure were accessed by computational analysis. The enzymatic performance was obtained by functional assay with the wild-type and mutant CYP21A2 proteins expressed in HEK293 cells. Computational analysis showed that p.W202R, p.E352V, and p.R484L have severely impaired the protein structure, while p.P35L, p.L199P, and p.P433L have moderate effects. The p.W202R, p.E352V, p.P433L, and p.R484L variants showed residual 21OH activity consistent with the simple virilizing phenotype. The p.P35L and p.L199P variants showed partial 21OH efficiency associated with the non-classical phenotype. Additionally, p.W202R, p.E352V, and p.R484L also modified the protein expression level. We have determined how the selected CYP21A2 gene mutations affect the 21OH activity through structural and activity alteration contributing to the future diagnosis and management of CYP21A2 deficiency.     

Composition,Structure, and Color of Fat Bloom Due to the Partial Liquefaction of Fat in Dark Chocolate

A type of fat bloom, which had not previously been fully characterized, was investigated to identify the state of its existence and its formation mechanism. Samples of bloom on solid chocolate resulting from the partial liquefaction of fat during temperature variations were analyzed to determine the crystal characteristics, fat contents, and triacylglycerol (TAG) compositions. Also, observation and elemental analyses were performed by scanning electron microscope with an energy-dispersive X-ray spectrometer, color analyses of minute regions were made by using PARISS^®, and Fourier-transform infrared (FT-IR) analyses were performed. The dark- and light-brown areas did not show any differences in fat content or TAG compositions that could lead to the observed color differences. Although differences in component distributions were noted in micrometer-sized regions, no relation to the colors was confirmed. The bloom samples in this study and bloom developed without a tempering process resembled each other in the tone of color at their discolored regions, but the states they adopted differed from one another. It is suggested that the color in this type of bloom was affected by the roughness and/or porosity of the microstructure and could also be a result of the coarsened fat crystal network and of the liquid fat migration.     

动植物油脂低温低压氢化技术及助剂的研究

使用了一种镍催化剂低温、低压加氢技术 ,同时使用了具有较好吸附性的助剂 ,来提高加氢效率。氢化工艺能达到低温、低压、短氢化时间。使氢化过程更加完善。确定了反应的优惠条件 :氢化反应时间为 10 0～ 110min ,反应温度为 10 0℃ ,催化剂用量为 0 5 5kg(相对于 10kg猪油 ) ,反应压力为 0 .5 5MPa。在这一反应条件下猪油氢化可得到熔点为 5 6～5 8℃ ,碘值≤ 2的硬脂酸用氢化油。加入助剂能平均缩短反应时间约 15min。可以平均降低压力 0 0 5MPa。     

Biochemical,Clinical, and Genetic Characteristics of Mexican Patients with Primary Hypertriglyceridemia,Including the First Case of Hyperchylomicronemia Syndrome Due to GPIHBP1 Deficiency

Primary hypertriglyceridemia (PHTG) is characterized by a high concentration of triglycerides (TG); it is divided between familial hyperchylomicronemia syndrome and multifactorial chylomicronemia syndrome. In Mexico, hypertriglyceridemia constitutes a health problem in which the genetic bases have been scarcely explored; therefore, our objective was to describe biochemical–clinical characteristics and variants in the APOA5, GPIHBP1, LMF1, and LPL genes in patients with primary hypertriglyceridemia. Thirty DNA fragments were analyzed using PCR and Sanger sequencing in 58 unrelated patients. The patients’ main clinical–biochemical features were hypoalphalipoproteinemia (77.6%), pancreatitis (18.1%), and a TG median value of 773.9 mg/dL. A total of 74 variants were found (10 in APOA5, 16 in GPIHBP1, 34 in LMF1, and 14 in LPL), of which 15 could be involved in the development of PHTG: 3 common variants with significative odds and 12 heterozygous rare pathogenic variants distributed in 12 patients. We report on the first Mexican patient with hyperchylomicronemia syndrome due to GPIHBP1 deficiency caused by three variants: p.R145*, p.A154_G155insK, and p.A154Rfs*152. Moreover, eleven patients were heterozygous for the rare variants described as causing PHTG and also presented common variants of risk, which could partially explain their phenotype. In terms of findings, two novel genetic variants, c.-40_-22del LMF1 and p.G242Dfs*10 LPL, were identified.