RESUMEN
D-bifunctional protein deficiency (#OMIM 261515) is a rare autosomal recessive hereditary metabolic disorder causing severe clinical and biochemical abnormalities that are usually fatal in the course of the first years of life. This disease is classified as single enzyme peroxisomal disorder affecting the ß-oxidation pathway in this compartment. In this paper we present a full overview of the clinical presentation, magnetic resonance imaging, biochemical and molecular data of two Slovak D-bifunctional protein deficient patients. In the clinical presentation of both patients severe generalized hypotonia, depression of neonatal reflexes, craniofacial dysmorphism and seizures dominated starting from the second day of life. In both patients, who died up to two years of life, we found elevated plasma levels of very long chain fatty acids and we identified the presence of causative mutations in the HSD17B4 gene. In the first case, we found the homozygous mutation c.46G>A, which is responsible for a defect in the dehydrogenase domain. In the second patient, the heterozygous mutations c.1369A>G and c.1516C>T were present and functionally they are related to the hydratase domain of the protein. This combination of mutations in the second patient is very rare and has not been reported until now. The presence of mutations was examined in all family members, and the resulting data were successfully utilized for prenatal diagnosis.
Asunto(s)
Encefalopatías Metabólicas/diagnóstico , Proteína-2 Multifuncional Peroxisomal/deficiencia , Secuencia de Bases , Encefalopatías Metabólicas/genética , Análisis Mutacional de ADN , Femenino , Heterocigoto , Humanos , Lactante , Masculino , Mutación Missense , Proteína-2 Multifuncional Peroxisomal/genética , Peroxisomas/enzimología , EslovaquiaRESUMEN
OBJECTIVE: To introduce QF-PCR method for detection of the most common chromosomal (trisomy 21, 18 and 13) and gonosomal aneuploidies at our department in the second-trimester amniotic fluid. To test the hypothesis of chromosomal aneuploidies detection using STR markers of Aneufast® kit via analysing free fetal DNA (ffDNA) isolated from plasma of pregnant women with confirmed trisomy 21 in fetus. DESIGN: A prospective clinical study. SETTING: Department of Obstetrics and Gynecology, Jessenius Faculty of Medicine and University Hospital in Martin, Slovak Republic. METHODS: The samples of amniotic fluid were obtained from 67 women (twin pregnancy in 3 cases) in the 2nd trimester (15th to 22nd gestational week (g.w.)). Samples were examined using multiplex QF-PCR via Aneufast kit. In the case of positivity for trisomy 21, they were re-examined using Devyser Resolution 21 kit. All samples were parallelly evaluated by cytogenetic karyotyping. We also analyzed ffDNA from the plasma of 3 high-risk women using Aneufast kit. The plasma samples were obtained in the 2nd trimester(17th to 21st g.w.). Qiaamp DSP Virus kit was used for ffDNA isolation. Trisomy 21 of 3 fetuses was confirmed by karyotyping after 2nd trimester amniocentesis. RESULTS: In the cohort of 70 samples, 7 pathological results (six trisomies 21 and one trisomy 18) were obtained. There was 100% concordance with cytogenetic karyotype in all samples examined by QF-PCR. The amplification of tracked chromosome 21 fragments was not evaluable in the case of ffDNA analysis. CONCLUSION: QF-PCR was approved as reliable, rapid, quite simple and financially bearable method of prenatal diagnostics. Despite the fact of good availability and work implementation of Aneufast® kit, results of ffDNA analysis are insufficient. We did not obtain interpretable results after ffDNA analysis from maternal plasma in trisomy 21 fetuses.
Asunto(s)
Líquido Amniótico/química , Aneuploidia , Cromosomas Humanos Par 18 , ADN/análisis , Síndrome de Down/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Diagnóstico Prenatal/métodos , Adulto , Amniocentesis , Cromosomas Humanos Par 21 , Síndrome de Down/genética , Femenino , Humanos , Cariotipificación , Embarazo , Segundo Trimestre del Embarazo , Estudios Prospectivos , Eslovaquia , TrisomíaRESUMEN
BACKGROUND: Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are distinctive diseases with severe impairment of psychomotoric development and behaviour. Both syndromes are caused by the loss of paternal (PWS) or maternal (AS) gene expression of chromosomal region 15q11-13. The work reveals the various causes of this loss. The choice of the most suitable method for screening of the genome mutations in the patients suspected of PWS and AS is another purpose of the work. METHODS AND RESULTS: The methyl specific analysis (MS PCR) in locus SNRPN, short tandem repeat (STR) analysis and fluorescent in situ hybridization (FISH) were used. In the group of 55 patients tested for PWS and AS only maternal allele was present in 11 patients and only paternal allele was present in 1 patient in the locus SNRPN: 10 microdeletions 15q11-13, 1 UPD(15)mat and 1 UPD(15)pat. CONCLUSIONS: MS PCR seems to be the most profitable method for the first step of selection of PWS patients. In positive cases is inevitable to use also additional tests of molecular diagnosis to distinguish the particular mechanism leading to the disorders. In AS patients is also MSPCR recommended as the first step although it is necessary to exclude mutation in UBE3A gene in case of MS PCR negativity.