Severe clinical manifestation of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase deficiency associated with two novel mutations: a case report.

BACKGROUND: Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (mHS) deficiency is an autosomal recessive inborn error of metabolism, which will give rise to failure of ketogenesis in liver during illness or fasting. It is a very rare disease with only a few patients reported worldwide, most of which had a good prognosis after proper therapies. CASE PRESENTATION: We report a 9-month-old boy with mHS deficiency presenting with unusually severe and persistent acidosis after diarrhea and reduced oral food intake. The metabolic acidosis persisted even after supplementation with sugar and alkaline solution. Blood purification and assisted respiration alleviated symptoms, but a second onset induced by respiratory infection several days later led to multiple organ failure and death. Urine organic acid analysis during the acute episode revealed a complex pattern of ketogenic dicarboxylic and 3-hydroxydicarboxylic aciduria with prominent elevation of glutaric acid and adipic acid, which seem to be specific to mHS deficiency. Plasma acylcarnitine analysis revealed elevated 3-hydroxybutyrylcarnitine and acetylcarnitine. This is the first report of elevated 3-hydroxybutyrylcarnitine in mHS deficiency. Whole exome sequencing revealed a novel compound heterozygous mutation in HMGCS2 (c.100C > T and c.1465delA). CONCLUSION: This severe case suggests the need for patients with mHS deficiency to avoid recurrent illness because it can induce severe metabolic crisis, possibly leading to death. Such patients may also require special treatment, such as blood purification. Urine organic acid profile during the acute episode may give a hint to the disease.

[Pedigree investigation of clinicopathologic features and alpha-galactosidase A gene mutation in a family with Fabry disease].

OBJECTIVE: To analyze the clinical manifestation, clinicopathologic features and alpha-galactosidase A (GLA) gene mutations in a pedigree with Fabry disease. METHODS: In this study, we retrospectively collected the clinical data of the members in the pedigree with Fabry disease, then the clinicopathologic features of the male proband were analyzed by renal biopsy, and GLA gene was detected by PCR and direct sequencing. RESULTS: 1) The proband was characterized by pigmentation of bilateral lower extremities, episodes of neuropathic pain, and renal dysfunction. The renal biopsy showed secondary focal segmental glomerulosclerosis with massive foam-cell liked podocytes under light microscope and abundant inclusions in podocytes which were round, comprising concentric layers of dense material separated by clear spaces under electron microscope. 2) The proband was identified to present a missense mutation as CAG119TAG (Q119T). The mother and niece of the proband were the carriers of this missense mutation. CONCLUSION: We identified a family with Fabry disease resulting from a novel point mutation of GLA gene, which has not been reported before in Chinese population.

[Identification of mutations in PKD1 and PKD2 genes in two Chinese families with autosomal dominant polycystic kidney disease].

OBJECTIVE: To identify the responsible mutation of autosomal dominant polycystic kidney disease (ADPKD) in two Chinese families. METHODS: Total genomic DNA of all available family members and 100 unrelated healthy controls was extracted from peripheral blood leukocytes using a standard phenol-chloroform procedure. All exons with intronic flanking sequences of the PKD1 and PKD2 genes in the probands were amplified by PCR. Mutations were detected directly by DNA sequencing. To evaluate the pathogenicity of the variations, family and control based analyses were performed. RESULTS: Five sequence variants were identified in the two families including PKD1 :c.2469G to A, PKD1:c.5014_5015delAG, PKD1:c.10529 C to T, PKD2:c.568G to A and PKD2:c.2020 1_2020delAG. Among them, PKD1:c.2469G to A and PKD2:c.2020 1_2020 delAG were novel mutations. Furthermore, the frameshift and splicing site mutations detected in the affected individuals were not detected in their unaffected relatives and 100 unrelated normal controls. CONCLUSION: PKD1:c.5014_5015delAG and PKD2:c.2020 1_2020delAG are the responsible mutations of family A and B, respectively, and PKD2:c.2020 1_2020delAG is a de novo mutation.

Improving quality management of newborn screening in southwest China.

OBJECTIVE: Newborn screening (NBS) programs benefit tens of millions of infants worldwide each year. However, the extremely large screening populations and number of laboratories involved pose great challenges to maintaining high screening quality. To achieve continuous quality improvement, we established a comprehensive quality management system (CQMS) in southwest China. METHODS: External quality assessment (EQA) and internal quality control were carried out for basic quality management. We used 16 quality indicators (QIs) to monitor the entire screening process, with external supervision from the China National Accreditation Service for Conformity Assessment. All retrospective data for quality assessment were collected consecutively from laboratory management and patient follow-up systems. RESULTS: From 2015 to 2019, satisfactory EQA performance was achieved, with an average score greater than 97 for each screening item. QI monitoring showed that NBS quality improved continuously. The rate of health education provision increased from 90.9% to 100% and the recall rate after a positive primary screening increased from 85.4% to 99.2%. The unsatisfactory specimen rate and rate of newborns lost to follow-up decreased to 0.38% and 0.08%, respectively. CONCLUSIONS: Implementing a CQMS and monitoring the whole screening process using QIs may yield continuous quality improvement of NBS.

Simultaneous quantification of fat-soluble vitamins A, 25-hydroxylvitamin D and vitamin E in plasma from children using liquid chromatography coupled to Orbitrap mass spectrometry.

The fat-soluble vitamins A, D, E and K are micronutrients essential for physiological activity, metabolism and growth. Accurate and sensitive analytical methods are needed to support growing research into fat-soluble vitamins and their impact on children's growth and health. Here we report the first method for simultaneous quantification of fat-soluble vitamins A (retinol), 25-hydroxylvitamin D2, 25-hydroxylvitamin D3, and vitamin E (α-tocopherol) using a Q-Exactive Orbitrap mass spectrometer in high-resolution, parallel reaction monitoring mode. This method can select desired ions with high efficiency, potentially making it superior to triple-quadrupole mass spectrometers that employ multiple reaction monitoring. The proposed method offers excellent accuracy, specificity, and sensitivity, as demonstrated with plasma samples from healthy children.

[Recent advances in studies on autosomal dominant adult polycystic kidney disease].

Adult polycystic kidney disease (APKD) is a severe autosomal dominant inheritable renal disease with high incidence. Because of the late-onset of the disease, patients might have transferred the disease gene to the next generation when diagnosis is made. Since its pathogenic molecular mechanism is still not completely clear and the shortage of effective medicines, the prevention and treatment of the disease is still not satisfactory. In the present article, the recent advances in the research on the pathogenesis, gene diagnosis and management of APKD are reviewed.

PLCε knockdown prevents serine/glycine metabolism and proliferation of prostate cancer by suppressing YAP.

The metabolic reprogramming is an important basis for the development of many tumors, including prostate cancer (PCa). Metabolic changes in many amino acids consist of serine and glycine affect the biological behavior of them. Phospholipase C epsilon (PLCε) plays an important role as an oncogene. However, its role in regulating amino acid metabolism remains unclear. In this study, results found significantly positive correlation between PLCε and Yes-associated protein (YAP) in PCa tissues. LC-MS/MS and GC-MS results further displayed abnormally elevated levels of serine, glycine and its some downstream metabolites in the blood of PCa patients. Secondly, PLCε knockdown can inhibit serine/glycine producing and proliferation of PCa both in vivo and in vitro. Mechanistically, PLCε may affect the serine/glycine metabolism by regulating dephosphorylation and nuclear translocation of YAP. More interestingly, verteporfin (VP, a specific inhibitor of YAP) could effectively enhance the PLCε-depletion induced inhibition of serine/glycine secretion and growth. Overall, this research revealed the possibility of anomalous serine/glycine levels in the blood for the diagnosis of PCa, identified the important role of the PLCε/YAP axis in regulating serine/glycine metabolism, cell proliferation and tumor growth, and suggested the combination of VP with PLCε-depletion may provide a new idea for the treatment of PCa.

microRNA-221 Enhances MYCN via Targeting Nemo-like Kinase and Functions as an Oncogene Related to Poor Prognosis in Neuroblastoma.

Purpose:MYCN is one of the most well-characterized genetic markers of neuroblastoma. However, the mechanisms as to how MYCN mediate neuroblastoma tumorigenesis are not fully clear. Increasing evidence has confirmed that the dysregulation of miRNAs is involved in MYCN-mediated neuroblastoma tumorigenesis, supporting their potential as therapeutic targets for neuroblastoma. Although miR-221 has been reported as one of the upregulated miRNAs, the interplay between miR-221 and MYCN-mediated neuroblastoma progression remains largely elusive.Experimental Design: The expression of miR-221 in the formalin-fixed, paraffin-embedded tissues from 31 confirmed patients with neuroblastoma was detected by locked nucleic acid-in situ hybridization and qRT-PCR. The correlation between miR-221 expression and clinical features in patients with neuroblastoma was assessed. The mechanisms as to how miR-221 regulate MYCN in neuroblastoma were addressed. The effect of miR-221 on cellular proliferation in neuroblastoma was determined both in vitro and in vivoResults: miR-221 was significantly upregulated in neuroblastoma tumor cells and tissues that overexpress MYCN, and high expression of miR-221 was positively associated with poor survival in patients with neuroblastoma. Nemo-like kinase (NLK) as a direct target of miR-221 in neuroblastoma was verified. In addition, overexpression of miR-221 decreased LEF1 phosphorylation but increased the expression of MYCN via targeting of NLK and further regulated cell cycle, particularly in S-phase, promoting the growth of neuroblastoma cells.Conclusions: This study provides a novel insight for miR-221 in the control of neuroblastoma cell proliferation and tumorigenesis, suggesting potentials of miR-221 as a prognosis marker and therapeutic target for patients with MYCN overexpressing neuroblastoma. Clin Cancer Res; 23(11); 2905-18. ©2016 AACR.