Prenatal Diagnosis Of Duchenne Muscular Dystrophy Research Articles

Analysis of results of prenatal diagnosis for 67 pedigrees affected with Duchenne muscular dystrophy in the central plain region of China

To retrospectively analyze the results of prenatal diagnosis for 67 pedigrees affected with Duchenne muscular dystrophy (DMD) from the Central Plain Region of China and explore the optimal diagnostic strategy. Probands from the 67 pedigrees were subjected to multiplex ligation-dependent probe amplification (MLPA), next-generation sequencing (NGS) and Sanger sequencing to attain the diagnosis. The fetuses were subjected to prenatal diagnosis, and the results were verified with short tandem repeat (STR) analysis. Among the 67 probands, large deletions, duplications and small mutations have accounted for 73.13% (49/67), 10.45% (7/67), and 16.42% (11/67), respectively. A hotspot deletion has involved exons 45 to 52. There were 11 small mutations, among which four were unreported previously. De novo mutations have accounted for 41.80% (28/67), of which 27 were novel large fragment deletions. Prenatal diagnosis was provided to 39 women who have carried the DMD gene mutations, 10 fetuses were identified as male patients and 7 fetuses were female carriers. Among the prenatal diagnosis results of 28 non-carrier pregnancies, one fetus was a male patient with the same mutation site as the proband. For the prenatal diagnosis of DMD, in addition to known pathogenic mutations, deletion of large fragments should also be excluded. Mothers of probands who do not carry the DMD mutation should also undergo prenatal diagnosis to rule out gonadal mosaicism.

Gestational Outcomes of Pregnant Women Who Have Had Invasive Prenatal Testing for the Prenatal Diagnosis of Duchenne Muscular Dystrophy

Aim To show the importance of prenatal diagnosis of Duchenne Muscular Dystrophy (DMD) and to demonstrate the effect of DMD gene mutations on gestational outcomes. Materials and Methods We retrospectively evaluated 89 pregnancies in 81 individuals who were referred to Hacettepe University for prenatal diagnosis of DMD between January 2000 and December 2015. Prenatal diagnostic methods (chorionic villus sampling (CVS): 66, amniocentesis (AC): 23) were compared for test results, demographic features, and obstetric outcomes of pregnancies. The female fetuses were divided into two groups according to the DMD status (healthy or carrier) to understand the effect of DMD gene mutations on obstetric outcomes. Results Eight prenatally diagnosed disease-positive fetuses were terminated. There was no statistically significant difference between the CVS and AC groups in terms of study variables. There were 46 male fetuses (51.6%) and 43 female fetuses (48.4%). Fifteen of the female fetuses were carriers (34.8%). Median birthweight values were statistically insignificantly lower in the carrier group. Conclusion Pregnancies at risk for DMD should be prenatally tested to prevent the effect of disease on families and DMD carrier fetuses had obstetric outcomes similar to DMD negative female fetuses.

Rapid method for targeted prenatal diagnosis of Duchenne muscular dystrophy in Vietnam

ObjectiveSince there is no effective curative treatment for Duchenne muscular dystrophy (DMD), prevention mostly depends on genetic counseling and prenatal diagnosis. About two-thirds of the affected patients have large deletions or duplications, which can be detected by multiplex ligation-dependent amplification (MLPA). The remaining cases include small mutations, which cannot be easily identified by routine techniques. In such cases, linkage analysis may be a useful tool for prenatal diagnosis. Here we compared results obtained from linkage using short tandem repeats (STRs) with those by MLPA and sequencing analysis. Materials and methodsEight Vietnamese pregnant women at risk of having a baby with DMD and requesting prenatal diagnosis were recruited in this study. MLPA and direct sequencing were applied to screen large rearrangements and point mutations in the dystrophin gene in the DMD probands and the fetal samples. STR linkage was also performed to analyze fetal mutation status. ResultsBy MLPA and sequencing analysis, five DMD patients showed deletions of the dystrophin gene, and no deletions of exons were detected in seven amniotic fluid cell samples; one patient harbored the out-of-frame small deletion of exon 43, which was also found in the fetal sample of this family. STR analysis revealed the transmission of a mutant allele inside each family. ConclusionOur results suggest that the combination of STR and MLPA could be a rapid, reliable, and affordable detection protocol for determination of the carrier's status and prenatal diagnosis of DMD in a developing country such as Vietnam.

Multiplex PCR for rapid detection of exonal deletions in patients of duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is the most common X-linked disorder in children affecting 1 in 3500 males. Since, as of now, we have no treatment for DMD, carrier detection and prenatal diagnosis is the most important preventive strategy. Multiplex PCR helps in rapid detection of hot spot exonal deletions (positive in 65% of cases) as many exons can be identified in a single run. 10 children with characterstic clinical features of DMD and chorionic villus samples of 10 antenatal patients with positive family history were studied. We identified a deletion mutation in exon 49 of the dystrophin gene in a 4 yr old boy referred with signs and symptoms suggestive of DMD using primers for exons 45, 48, 49, 43, 44, 19, 3, 8, 13 and muscle promoter, subjected to multiplex polymerase chain reaction (PCR) and agarose/Nu-Sieve gel electrophoresis. These genetic methods aid in prenatal diagnosis of DMD as well as confirmation of diagnosis in children with signs and symptoms suggestive of the disease.

Duchenne muscular dystrophy and spinal muscular atrophy type I segregating in the same family.

We report on a family with two severe neuromuscular diseases: Duchenne muscular dystrophy (DMD) and acute infantile spinal muscular atrophy (SMA I). One boy has DMD, and his brother died of SMA I at 11 months of age. Both boys had received the same DMD allele from their mother. Analysis of dystrophin by immunohistochemistry and Western blot showed complete lack of dystrophin in both brothers. The mother had a partial deficiency of dystrophin. The boy with SMA I had increased levels of creatine kinase in serum, compatible with DMD, but the muscle biopsy and post-mortem examination of the spinal cord showed the typical changes of SMA I. There were no cytogenetic abnormalities explaining the occurrence of both DMD and SMA I in this family. Molecular genetic prenatal diagnosis of DMD and SMA I, using analysis of RFLPs and dinucleotide repeats, has been performed in one foetus in the family. The results showed that the foetus had a high risk of developing SMA I. An abortion was planned but the pregnancy was terminated by miscarriage.

Use of dystrophin genomic and cDNA probes for solving difficulties in carrier detection and prenatal diagnosis of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) results from mutations in the X-linked gene coding for the muscular protein dystrophin. The isolation of genomic and cDNA probes for this gene has greatly facilitated the detection of DMD carriers, which previously relied mainly on measurements of serum creatine kinase (CK), and has enabled prenatal diagnosis of this disease. However, the relatively large size of the gene and the high frequency of recombination and mutation events within the dystrophin locus continue to pose difficulties in the genetic counselling and prenatal diagnosis of DMD, and render the conclusions of molecular analysis less clear cut. This communication presents examples of two such difficulties: the distinction between sporadic and inherited cases in families with a single patient and normal CK levels in all females, and the distinction between mutant and normal dystrophin alleles in families in which the patients have died. The combined use of genomic and cDNA probes allows one to make these distinctions. An additional complicating factor, gonadal mosaicism, is demonstrated.

Detection of deletions spanning the Duchenne muscular dystrophy locus using a tightly linked DNA segment.

The Duchenne muscular dystrophy (DMD) locus has been localized to the short arm of the human X chromosome (Xp21) by detection of structural abnormalities and by genetic linkage studies. A library highly enriched for human DNA from Xp21 was constructed using DNA isolated from a male patient who had a visible deletion and three X-linked disorders (DMD, retinitis pigmentosa and chronic granulomatous disease). Seven cloned DNA probes from this library and the probe 754 (refs 5, 8) are used in the present study to screen for deletions in the DNA isolated from 57 unrelated males with DMD. Five of these DMD males are shown to exhibit deletions for one of the cloned DNA segments and at least 38 kb of surrounding DNA. In addition, two subclones from the same region detect four restriction fragment length polymorphisms which exhibit no obligate recombination with DMD in 34 meiotic events. These new DNA segments will complement the existing Xp21 probes for use in carrier detection and prenatal diagnosis of DMD. Elucidation of the end points of the five deletions will help delineate the extent of the DMD locus and ultimately lead to an understanding of the specific sequences involved in DMD.

Prenatal diagnosis of duchenne muscular dystrophy: failure of amniotic fluid and maternal serum Nτ-methylhistidine analyses to detect affected fetuses

Nτ-Methylhistidine (MH) and creatinine levels were determined in amniotic fluid and maternal serum from 81 women undergoing midtrimester amniocentesis for reasons other than the diagnosis of neuromuscular disease. Samples were also examined in three pregnancies with male fetuses who were subsequently found to have Duchenne muscular dystrophy (DMD). Between 16 and 20 weeks' gestation, amniotic fluid and maternal serum MH levels averaged 3.22 and 1.94 μmoles/L, respectively. No significant differences were found between the control and affected fetuses for MH and creatinine levels or for MH/creatinine ratios from amniotic fluid or maternal serum. Determination of amniotic fluid MH level thus has no apparent value in the prenatal diagnosis of DMD.