Carriers Of Duchenne Muscular Dystrophy Research Articles

Assessing the barriers to cardiac care in carriers of Duchenne and Becker muscular dystrophy.

Duchenne and Becker muscular dystrophy (DBMD) are X-linked conditions causing progressive muscle weakness, muscle wasting, and cardiomyopathy in affected males. Two-thirds of cases of DBMD are inherited from a carrier female while one-third of cases occur sporadically. Women who are DBMD carriers typically do not manifest noticeable muscular symptoms. However, about 10% may develop cardiomyopathy while up to 60% are at risk for cardiac abnormalities including myocardial damage, fibrosis, and abnormalities detectable by echocardiogram and electrocardiogram (EKG). The American Academy of Pediatrics (AAP) recommends that carriers of DBMD receive a complete cardiac evaluation beginning at age 25-30 which includes an echocardiogram and EKG, with re-evaluation at least every 5years. As many as 54.5% carriers may not be adhering to the AAP recommendations (Bogue et al., 2016). This study was conducted to define the perceived challenges carriers of DBMD face in obtaining cardiac care. A questionnaire was completed by 60 carriers of DBMD recruited through The Duchenne Registry to determine their current cardiac care practices. The majority of carriers surveyed (71.7%, 43/60) self-reported obtaining appropriate cardiac care while 28.3% (17/60) of carriers surveyed did not. Eleven semi-structured telephone interviews were conducted with a subset of those who completed the questionnaire. Individuals were eligible for telephone interview if they had not: (a) seen a cardiologist in the last 5years, (b) had an echocardiogram in the last 5years, or (c) had an EKG in the last 5years. The primary theme identified from this cohort was a perceived lack of awareness among healthcare providers regarding cardiac risks in carriers (11/11). Increased awareness, health education regarding risks for carriers, and advocacy efforts are needed for healthcare providers and DBMD carriers in order to ensure that this entire population receives the cardiac care they need.

Development of CRISPR-Mediated Systems in the Study of Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is a severe type of X-linked recessive degenerative muscle disease caused by mutations in the dystrophin (DMD) gene on the X chromosome. The DMD gene is complex, consisting of 79 exons, and mutations cause changes in the DMD mRNA so that the reading frame is altered, and the muscle-specific isoform of the dystrophin protein is either absent or truncated with variable residual function. The emerging CRISPR-Cas9-mediated genome editing technique is being developed as a potential therapeutic approach to treat DMD because it can permanently replace the mutated dystrophin gene with the normal gene. Prenatal DNA testing can inform whether the female fetus is a carrier of DMD, and the male fetus has inherited a mutation from his mother (50% chance of both). This article summarizes the present status of current and future treatments for DMD.

Inflammation-induced fibrosis in skeletal muscle of female carriers of Duchenne muscular dystrophy

Female carriers of DMD gene mutations may be symptomatic and show variable skeletal as well as cardiac muscle symptoms. Skeletal muscle can exhibit morphological alterations. However, inflammatory, degenerative and fibrotic changes as seen in Duchenne boys have not been specifically analysed yet, so we addressed the question whether skeletal muscle of female carriers show such alterations. Thirteen carriers with an age range of 3 to 50 years were studied retrospectively. Five out of 13 women had clinically affected relatives. Clinically, most women showed mild muscle weakness, while the CK levels were increased in nine of them. Histomorphological analyses highlighted the typical mosaic pattern of dystrophin-positive and -negative fibres. Regenerating fibres were diffusely scattered and focally pronounced, while endo- and perimysial fibrosis was a variable but constant feature. Infiltration of CD206+TGFß+ macrophages and scattered T cells was noted in the endomysium. TGFb and CCL18, were significantly increased. However, gene expression of markers involved in Th1/Th2 immunity did not reach statistical significance compared to non-diseased controls. In summary, skeletal muscle of clinically manifest female DMD gene mutation carriers shows mild fibrosis and increased regeneration associated with endomysial CD206+TGFβ+ and STAT6+ macrophages, which are most likely involved in fibrotic remodelling.

DUCHENNE AND BECKER MUSCULAR DYSTROPHY CARRIERS: EVIDENCE OF CARDIOMYOPATHY BY EXERCISE AND CARDIAC MAGNETIC RESONANCE IMAGING

Lack of defined parameters and varied detection methods have resulted in a broad range of predictions on the prevalence of cardiac disease in carriers of Duchenne and Becker muscular dystrophy (DMD and BMD). Prior studies have been small retrospective samples without genotype confirmation. No study

Clinical and genetic characteristics of female dystrophinopathy carriers.

The present study aimed to determine the genetic status of manifesting carriers (MCs) of Duchenne muscular dystrophy (DMD)/Becker muscular dystrophy (BMD) and asymptomatic carriers with a family history of DMD/BMD, and identify potential simple and reliable methods for screening dystrophinopathy carriers. Clinical data from probable carriers and MCs were collected and analyzed. MCs underwent multiplex ligation-dependent probe amplification (MLPA) for dystrophin gene exons combined with muscle disease panel test based on a next-generation sequencing (NGS) platform. In addition, the status of probable carriers was determined by MLPA or Sanger sequencing, according to the mutations of probands. A total of 154 female were enrolled, among which 78 cases were found to be carriers, including 4 MCs and 74 asymptomatic female carriers. The 4 MCs exhibited duplication mutations. Among the 74 asymptomatic carriers, 41.89% harbored deletion mutations, including 2 cases with suspected germline mosaicism and no mutation in the dystrophin gene, while 44.59% harbored point mutations in exons and only 10 cases (13.51%) carried duplication mutations. The area under the receiver operating characteristic (ROC) curve of creatine kinase (CK) was 0.822, with a sensitivity of 65.38% and specificity of 92.1%. In addition, DMD was positively correlated with the CK, alanine transaminase and aspartate transaminase levels of the carriers. MLPA for exons of the dystrophin gene, along with NGS and Sanger sequencing, was effective for the diagnosis of MCs and for determining the status of probable carriers. The ROC curve analysis also demonstrated that CK level was an excellent predictor for distinguishing DMD/BMD carriers.

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.

A De novo Mutation in Dystrophin Causing Muscular Dystrophy in a Female Patient.

Background:Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive neuromuscular diseases resulting from dystrophin (DMD) gene mutations. It has been known that the carrier of DMD mutations may also have symptoms of the disease. While de novo mutation is quite common in BMD/DMD patients, it is rarely reported in the female carriers.Methods:Two sporadic Chinese patients with progressive muscular dystrophy and their familial members were recruited. The targeted next-generation sequencing (NGS) and the multiplex ligation-dependent probe analysis (MLPA) were performed in the proband. Blood tests, electrocardiography, echocardiography, and electromyography were also evaluated.Results:Two novel mutations of DMD gene were identified, c.7318C>T (p.Q2440*) in the male proband and c.4983dupA (p.A1662Sfs*24) in the female carrier. The MLPA analysis did not detect any large rearrangements. The haplotype analysis indicated that the two mutations were derived from de novo mutagenesis.Conclusions:We identified two novel de novo mutations of DMD gene in two Chinese pedigrees, one of which caused a female patient with muscular dystrophy. The mutational analysis is important for DMD patients and carriers in the absence of a family history. The NGS can help detect the mutations in MLPA-negative patients.

Abstract 415: Transgenic Expression of Dimethylarginine Dimethylaminohydrolase Attenuates Exercise-induced Fatigue in Duchenne Muscular Dystrophy Carrier Mice

Duchenne muscular dystrophy (DMD) is an X-linked disease caused by mutations in dystrophin and characterized by muscle degeneration, cardiomyopathy, and impaired muscle nitric oxide (NO) production that disrupts muscle blood flow regulation and leads to excessive post-exercise fatigue. Interestingly, circulating levels of the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) are elevated in dystrophin-deficient subjects. Therefore, we hypothesized that excessive circulating ADMA impairs muscle NO production and thus negatively impacts exercise tolerance in DMD. The objectives of this study were to determine whether increased circulating ADMA is itself sufficient to affect exercise performance, and whether transgenic modulation of ADMA metabolism could improve exercise-induced fatigue in the mdx mouse model of DMD. Although infusion of exogenous ADMA did impair exercise performance in healthy, wild-type mice, transgenic expression of dimethylarginine dimethylaminohydrolase 1 (DDAH), the enzyme that degrades ADMA, did not affect exercise-induced fatigue in dystrophin-deficient male mdx mice. Surprisingly, DDAH transgene expression did attenuate exercise-induced fatigue in dystrophin-heterozygous female mdx carrier mice. This improvement in exercise tolerance was associated with reduced heart weight, improved cardiac contractile function, and improved chronotropic responsiveness to beta-adrenergic stimulation in DDAH-transgenic female mdx carriers. In contrast, DDAH transgene expression did not significantly affect skeletal muscle pathology in female mdx carriers. We conclude that DDAH transgene expression improves exercise tolerance in dystrophin-heterozygous females, possibly by limiting pathological cardiac remodeling and helping to maintain heart performance. These findings emphasize the importance of methylated arginines to the development of cardiomyopathy in female DMD carriers, and have interesting implications for current genetic therapies that may only partially restore dystrophin expression in the hearts of male DMD patients.

50 Years Ago in The Journal of Pediatrics: An Assessment of the Creatine Kinase Test in the Detection of Carriers of Duchenne Muscular Dystrophy

50 Years Ago in The Journal of Pediatrics: An Assessment of the Creatine Kinase Test in the Detection of Carriers of Duchenne Muscular Dystrophy

Skewed X-chromosome inactivation plays a crucial role in the onset of symptoms in carriers of Becker muscular dystrophy.

Becker muscular dystrophy (BMD) is an X-linked recessive disorder affecting approximately 1: 18.000 male births. Female carriers are usually asymptomatic, although 2.5-18% may present muscle or heart symptoms. In the present study, the role of the X chromosome inactivation (XCI) on the onset of symptoms in BMD carriers was analysed and compared with the pattern observed in Duchenne muscular dystrophy (DMD) carriers. XCI was determined on the lymphocytes of 36 BMD carriers (both symptomatic and not symptomatic) from 11 families requiring genetic advice at the Cardiomyology and Medical Genetics of the Second University of Naples, using the AR methylation-based assay. Carriers were subdivided into two groups, according to age above or below 50years. Seven females from the same families known as noncarriers were used as controls. A Student's t-test for nonpaired data was performed to evaluate the differences observed in the XCI values between asymptomatic and symptomatic carriers, and carriers aged above or below 50years. A Pearson correlation test was used to evaluate the inheritance of the XCI pattern in 19 mother-daughter pairs. The results showed that symptomatic BMD carriers had a skewed XCI with a preferential inactivation of the X chromosome carrying the normal allele, whereas the asymptomatic carriers and controls showed a random XCI. No concordance concerning the XCI pattern was observed between mothers and related daughters. The data obtained in the present study suggest that the onset of symptoms in BMD carriers is related to a skewed XCI, as observed in DMD carriers. Furthermore, they showed no concordance in the XCI pattern inheritance.

Long-Term Pathological Follow-Up of Myocardium in a Carrier of Duchenne Muscular Dystrophy With Dilated Cardiomyopathy

Duchenne muscular dystrophy (DMD) is a fatal X-linked disorder, with an incidence of ≈1 in 3600 to 6000 male births. DMD is caused by mutations in the dystrophin gene located at Xp21.2 and is clinically characterized by progressive muscle degeneration and dilated cardiomyopathy (DCM). Some female DMD carriers show a variety of clinical manifestations, ranging from creatine kinase elevation to severe muscle weakness. DCM has been reported in 8% to 18% of female DMD carriers and sometimes results in a lethal course. Here, we describe long-term follow-up observations of myocardial changes in a DMD carrier with DCM. A 29-year-old female presented with progressive shortness of breath, increasing ankle edema, and orthopnea after a full-term normal delivery. A chest X ray showed cardiomegaly and bilateral pleural effusions, and echocardiography showed a severely reduced left ventricular ejection fraction of 24%, with a markedly increased left ventricular end-diastolic diameter of 71 mm. She was admitted for heart failure, and her symptoms improved with furosemide and inotropes. There were no symptoms to suggest myopathy, and blood analysis revealed no elevation of creatine kinase (60 U/L). Her newborn boy showed extreme elevation of creatine kinase (105 868 U/L) and was diagnosed with DMD …

Cardiac involvement in female carriers of duchenne or becker muscular dystrophy.

The significance of abnormal cardiac measures in asymptomatic females who harbor dystrophin gene mutations is controversial. Echo-measures of ventricular function were compared with published norms in a cross-sectional study of 130 (age, 39 ± 15.7 years) "carriers" of Duchenne or Becker muscular dystrophy (DMD/BMD). Correlations between cardiomyopathy (CM) and mutation, creatine kinase (CK) levels, age, and muscle symptoms were investigated. Depending on definition, CM prevalence was 3-33%. Ejection fraction (Simpson method) was < 55% in 9 (13%) and < 40% in 2 (2.9%). Eleven (8.5%) had wall motion abnormalities. Left ventricular end-systolic dimensions were increased in 7 (5.7%) and end-diastolic in 17 (13.9%). CM did not correlate with mutation type, DMD or BMD phenotype, CK level, muscle symptoms, or age. Occult CM can be found by screening in DMD/BMD carriers. Its lack of age-correlation suggests that not all abnormalities progress. Optimum screening schedules require a better understanding of progressive CM. Muscle Nerve 55: 810-818, 2017.

Induction of Pluripotent Stem Cells from a Manifesting Carrier of Duchenne Muscular Dystrophy and Characterization of Their X-Inactivation Status.

Three to eight percent of female carriers of Duchenne muscular dystrophy (DMD) develop dystrophic symptoms ranging from mild muscle weakness to a rapidly progressive DMD-like muscular dystrophy due to skewed inactivation of X chromosomes during early development. Here, we generated human induced pluripotent stem cells (hiPSCs) from a manifesting female carrier using retroviral or Sendai viral (SeV) vectors and determined their X-inactivation status. Although manifesting carrier-derived iPS cells showed normal expression of human embryonic stem cell markers and formed well-differentiated teratomas in vivo, many hiPS clones showed bi-allelic expression of the androgen receptor (AR) gene and loss of X-inactivation-specific transcript and trimethyl-histone H3 (Lys27) signals on X chromosomes, suggesting that both X chromosomes of the hiPS cells are in an active state. Importantly, normal dystrophin was expressed in multinucleated myotubes differentiated from a manifesting carrier of DMD-hiPS cells with XaXa pattern. AR transcripts were also equally transcribed from both alleles in induced myotubes. Our results indicated that the inactivated X chromosome in the patient's fibroblasts was activated during reprogramming, and XCI occurred randomly during differentiation.

Outdated risk assessment in a family with Duchenne dystrophy: Implications for duty to reassess.

Carrier risk assessment for Duchenne muscular dystrophy (DMD) is necessary to counsel women at risks of developing cardiomyopathy and having a child with DMD. Comprehensive molecular testing for dystrophin gene mutations has only been available since 20031; women counseled earlier have outdated risk assessments. We present a 5-generation family in whom results of familial mutation testing for DMD newly identified 10 obligate carriers and 28 women at risk to be carriers for DMD.

Knowledge of carrier status and barriers to testing among mothers of sons with Duchenne or Becker muscular dystrophy

Our study objective was to survey female carriers for Duchenne and Becker muscular dystrophy to identify barriers to carrier testing and the impact of carrier risk knowledge on cardiac and reproductive health management. We surveyed women who have or had biological sons with Duchenne or Becker muscular dystrophy and were enrolled in the US DuchenneConnect patient registry, with questions assessing knowledge of carrier status and recurrence risk, knowledge of care standards for carriers, and barriers to testing. Of the 182 eligible respondents, 25% did not know their carrier status and 14% incorrectly classified themselves as not at risk. Cost of testing was the most commonly identified barrier to testing. Women reporting unknown carrier status were 13 times as likely to express uncertainty regarding their recurrence risk compared to women reporting positive carrier status. 37% of women at an increased risk for cardiomyopathy had never had an echocardiogram. Women who were certain of their positive carrier status were twice as likely to have had an echocardiogram in the last five years compared to women with unknown carrier status. Future research on reducing barriers to counseling and carrier testing, such as cost, may improve care standard adherence.

Determining the role of skewed X-chromosome inactivation in developing muscle symptoms in carriers of Duchenne muscular dystrophy.

Duchenne and Becker dystrophinopathies (DMD and BMD) are X-linked recessive disorders caused by mutations in the dystrophin gene that lead to absent or reduced expression of dystrophin in both skeletal and heart muscles. DMD/BMD female carriers are usually asymptomatic, although about 8% may exhibit muscle or cardiac symptoms. Several mechanisms leading to a reduced dystrophin have been hypothesized to explain the clinical manifestations and, in particular, the role of the skewed XCI is questioned. In this review, the mechanism of XCI and its involvement in the phenotype of BMD/DMD carriers with both a normal karyotype or with X;autosome translocations with breakpoints at Xp21 (locus of the DMD gene) will be analyzed. We have previously observed that DMD carriers with moderate/severe muscle involvement, exhibit a moderate or extremely skewed XCI, in particular if presenting with an early onset of symptoms, while DMD carriers with mild muscle involvement present a random XCI. Moreover, we found that among 87.1% of the carriers with X;autosome translocations involving the locus Xp21 who developed signs and symptoms of dystrophinopathy such as proximal muscle weakness, difficulty to run, jump and climb stairs, 95.2% had a skewed XCI pattern in lymphocytes. These data support the hypothesis that skewed XCI is involved in the onset of phenotype in DMD carriers, the X chromosome carrying the normal DMD gene being preferentially inactivated and leading to a moderate-severe muscle involvement.

Detection of the mutation may guide treatment of heart and muscle in Duchenne muscular dystrophy.

We read with great interest the article, by Kono et al, about a 32-year-old male with Duchenne muscular dystrophy (DMD), who was admitted for dilated cardiomyopathy manifesting as heart failure, left bundle branch block, Mobitz-II block, bradycardia, and arterial hypotension. He profited from implantation of a cardiac resynchroniza-tion therapy-D system with a defibrillator and beta-blocker treatment. 1 We have the following comments and concerns. Diagnosing DMD only by muscle biopsy is insufficient. The diagnosis needs to be confirmed by genetic studies. 2 Was the patient investigated for deletions, duplications , or point mutations in the DMD gene? Which were the results of the Western blot for dystrophin? Was there complete absence of dystrophin or were there indications for a truncated protein, compatible with the diagnosis of Becker muscular dystrophy (BMD)? Since the patient was quite old for DMD, it has to be convincingly shown that BMD was definitively excluded. Diagnosing DMD on a molecular genetic level is important as genetic therapy in form of exon skipping is available for a certain type of mutations. 3 It has been shown that patients with DMD profit from the administration of ste-roids, usually deflazacort. 4 There are indications that steroids not only improve the performance of the skeletal muscle but also improve cardiac functions. 5 Furthermore, steroids reduce the myocardial fibrosis burden in these patients as has been shown by cardiac magnetic resonance imaging (MRI). 6 Did the presented patient receive steroids in addition to heart failure therapy? Did he profit from steroids with regard to cardiac and muscle function? Which side effects did he develop from steroids? Dilated cardiomyopathy in DMD is characterized by replacement of the myocar-dium with connective tissue. 6 Myocardial fibrosis in DMD can be best documented by application of cardiac MRI and administration of gadolinium to assess the amount of late gadolinium enhancement (LGE). 6 Did the patient undergo cardiac MRI and was gadolinium administered to assess the amount and location of myocardial fibrosis? Assessment of LGE in DMD is important since the amount of LGE strongly correlates with left ventricular systolic dysfunction. 6 Approximately two-thirds of the DMD patients inherit the mutation from their mothers. DMD carriers may manifest clinically or biochemically. Was the mother of the described patient investigated for her carrier status? Did she manifest clinically or were there other indications for being a DMD carrier? Did she undergo electrocardiography

Myocardial late gadolinium enhancement is associated with clinical presentation in Duchenne muscular dystrophy carriers.

BackgroundDuchenne muscular dystrophy (DMD) is an X-linked recessive disease that occurs in males leading to immobility and death in early adulthood. Female carriers of DMD are generally asymptomatic, yet frequently develop dilated cardiomyopathy. This study aims to detect early cardiac manifestation in DMD using cardiovascular magnetic resonance (CMR) and to evaluate its association with clinical symptoms.MethodsClinical assessment of DMD carriers included six minutes walk tests (6MWT), blood analysis, electrocardiography, echocardiography, and CMR using FLASH sequences to detect late gadolinium enhancement (LGE). T1-mapping using the Modified Look-Locker Inversion recovery (MOLLI) sequence was performed quantify extracellular volume (ECV).ResultsOf 20 carriers (age 39.47 ± 12.96 years) 17 (89.5 %) were clinically asymptomatic. ECV was mildly elevated (29.79 ± 2.92 %) and LGE was detected in nine cases (45 %). LGE positive carriers had lower left ventricular ejection fraction in CMR (64.36 ± 5.78 vs. 56.67 ± 6.89 %, p = 0.014), higher bothCK (629.89 ± 317.48 vs. 256.18 ± 109.10 U/l, p = 0.002) and CK-MB (22.13 ± 5.25 vs. 12.11 ± 2.21 U/l, p = 0.001), as well as shorter walking distances during the 6MWT (432.44 ± 96.72 vs. 514.91 ± 66.80 m, p = 0.037). 90.9 % of subjects without LGE had normal pro-BNP, whereas in 66.7 % of those presenting LGE pro-BNP was elevated (p = 0.027). All individuals without LGE were in the NYHA class I, whereas all those in NYHA classes II and III showed positive for LGE (p = 0.066).ConclusionsMyocardial involvement shown as LGE in CMR occurs in a substantial number of DMD carriers; it is associated with clinical and morphometric signs of incipient heart failure. LGE is thus a sensitive parameter for the early diagnosis of cardiomyopathy in DMD carriers.Trial registrationClinicaltrials.gov, NCT01712152 Trial registration: October 19, 2012.First patient enrolled: September 27, 2012 (retrospectively registered).

An Unusual Triad in Pediatric Neurology: A Case Report on Cerebral Palsy, Epilepsy, and Duchenne Muscular Dystrophy.

We present a case of an unusual triad in pediatric neurology: a currently 12-year-old boy with cerebral palsy and epilepsy who was later also diagnosed with Duchenne muscular dystrophy. We describe the clinical path that resulted in this exceptional diagnosis. This case report illustrates how different neurological disorders may overshadow each other. In addition, it demonstrates that every child with cerebral palsy and either an atypical clinical course or with inexplicable laboratory values—as well as every infant boy born to a theoretical Duchenne muscular dystrophy carrier—should be subjected to additional investigations.

Study on preimplantation genetic diagnosis and follow-up for Duchenne muscular dystrophy

Objective To carry out preimplantation genetic diagnosis (PGD) for Duchenne muscular dystrophy (DMD) carrier, so as to prevent the birth of affected infants with DMD. Methods One DMD gene carrier with a deletion of exon 10-30 received fertilization with intracytoplasmic sperm injection (ICSI). DMD gene and haplotype were tested after amplification of genome DNA in multiple displacement amplification (MDA), then healthy embryos were transferred to uterus according to the genetic results. Genetic testing was made in second trimester and after delivery, and also periodic follow-up was made for over 3 years. Results The second cycle of PGD was successful, and a total of 14 single blastomeres obtained from 7 embryos were used for genetic analysis. The success rate of MDA was 13/14, and the allele dropout rate was 18.75% (18/96). Three unaffected embryos were transferred, resulting in twin pregnancy. One healthy boy and one healthy girl were born in cesarean section at the pregnant week of 35. Genetic results on DNA from both amniotic fluid at 16 weeks of gestation and peripheral blood after birth were normal. During the 3-year follow-up, both 2 infants were normal in growth and development, motor function and dynamic monitor of serum creatine kinase (CK). Conclusions Preimplantation genetic diagnosis can help DMD gene carrier give birth to healthy infants, and these infants have normal development. DOI: 10.3969/j.issn.1672-6731.2015.06.008