RESUMEN
Malonyl-CoA decarboxylase deficiency is an extremely rare autosomal recessive inborn error of fatty acid metabolism. It usually follows a severe disease course and presents poor prognosis without treatment. Here, we report an affected female juvenile with a mild clinical and biochemical phenotype who mainly featured poor schooling without cardiomyopathy and metabolic acidosis. She was suspected of malonyl-CoA decarboxylase deficiency due to a 57-kb deletion in 16q23.3 encompassing the MLCYD gene revealed by chromosome microarray. Malonyl-CoA decarboxylase deficiency was then confirmed by acylcarnitine analysis and organic acid analysis. Real-time PCR analysis of the patient revealed the first three exon deletion of the MLYCD gene, which was maternally inherited. DNA sequencing of the MLYCD gene of the patient identified a novel heterozygous mutation (c.911G>A, p.G304E) in exon 4 that was paternally inherited. The patient urine malonic acid dissolved and had a better school record in 6 month after initiation of fat-limited diet. At 1 year post treatment, the blood malonylcarnitine level decreased remarkably. Our result expands the phenotype of malonyl-CoA decarboxylase deficiency and suggests attentions should be paid to the mild form of disorders, for example, malonyl-CoA decarboxylase deficiency, which usually present a severe disease course.
Asunto(s)
Acidosis/genética , Carboxiliasas/deficiencia , Errores Innatos del Metabolismo/genética , Acidosis/fisiopatología , Adolescente , Secuencia de Bases , Carboxiliasas/genética , Cardiomiopatías/genética , Cardiomiopatías/fisiopatología , Niño , Cromosomas/genética , Exones , Femenino , Humanos , Malonatos/metabolismo , Malonil Coenzima A/genética , Errores Innatos del Metabolismo/fisiopatología , Ácido Metilmalónico , Análisis por Micromatrices , Eliminación de SecuenciaRESUMEN
OBJECTIVE: To analyze the clinical characteristics of three Chinese cases of Niemann-Pick disease type C patients with neonatal cholestasis as initial presentation, and enhance awareness of Niemann-Pick disease type C among pediatricians. METHOD: Three sporadic cases with confirmed Niemann-Pick disease type C initially presented as neonatal cholestasis were retrospectively reviewed in this study. Their peripheral blood specimens were collected after obtaining informed consent. All exons and the intron-exon boundaries of NPC1 gene were examined by bi-directional sequencing. RESULT: Three patients, 1 female and 2 males, aged from 2 months to 5 years and 10 months, all first complained of jaundice in the neonatal period. Laboratory tests showed total bilirubin and direct bilirubin significantly increased with predominant increase of direct bilirubin. Total bile acid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were also increased, while high-density lipoprotein cholesterol decreased. All patients were also accompanied by hepatosplenomegaly, with two of them having increased bronchovascular markings in chest X-ray. Two heterozygous changes of NPC1 gene, c.2741G>T +c.3020C>G (p. C914F + p. P1007R), c.2177G>C + c.3734_ 3735delCT (p.R726T + p. P1245RfsX12), and c.2054T>C + c.2128C>T(p.I685T + p.Q710X), were identified in patient 1, 2 and 3, respectively. CONCLUSION: We reported three cases suffered from Niemann-Pick disease type C with initial presentation as neonatal cholestasis in the mainland of China. For newborns with prolonged jaundice in the neonatal period, as well as neonatal cholestasis, hepatosplenomegaly, Niemann-Pick type C should be included in consideration of differential diagnosis. Genetic testing can identify causative mutations for diagnosis.
Asunto(s)
Colestasis/etiología , Enfermedad de Niemann-Pick Tipo C/diagnóstico , Pueblo Asiatico , Ácidos y Sales Biliares , Bilirrubina , Niño , Preescolar , China , Exones , Femenino , Humanos , Lactante , Recién Nacido , Enfermedades del Recién Nacido , Lipoproteínas HDL , Masculino , Mutación , Enfermedad de Niemann-Pick Tipo C/complicaciones , Enfermedad de Niemann-Pick Tipo C/genética , Enfermedad de Niemann-Pick Tipo C/patología , Enfermedades de Niemann-Pick , Estudios Retrospectivos , EsplenomegaliaRESUMEN
OBJECTIVE: To analyze the clinical characteristics of the patient with tyrosine hydroxylase deficiency, and investigate it's molecular mechanism. METHOD: The clinical characteristics of a patient with tyrosine hydroxylase deficiency were summarized and analyzed, his and his family's peripheral blood specimens were collected after informed consent was signed. All exons and the intron-exon boundaries of guanosine triphosphate hydroxylase I gene, tyrosine hydroxylase gene and sepiapterin reductase gene were examined by DNA-PCR, bi-directional sequencing. RESULT: The patient was a 3-year-old boy, presented with unexplained dystonia for 3 years, without significant impairment of intelligence. Physical examination showed limb muscle strength grade V, rigidity of extremities, hypertonicity, brisk deep tendon reflexes in limbs, without obvious abnormalities in auxiliary examination, such as brain MRI, hepatic biochemical panel, creatine kinase, and ceruloplasmin. He dramatically responded to small doses of levodopa in the follow-up for half a year. A homozygous missense change in exon 5 of TH gene, c.605G > A (p.R202H), which was a known pathogenic mutation, was found in the patient. His parents were heterozygous for the R202H mutation. CONCLUSION: The age of onset in tyrosine hydroxylase deficiency patients is usually within the first year of life. Unexplained dystonia and hypokinesia were the main clinical features of tyrosine hydroxylase deficiency. The dopa-responsive effects for some patients are so obvious that we should strengthen awareness of the disease. TH gene c.605G > A (p.R202H) may be a common type of causative mutations for the mild form at home and abroad.
