Screening for Duchenne muscular dystrophy in Germany, 1977-2011: A personal story.

EDITOR'S NOTE: This article by Dr. Günter Scheuerbrandt is a fascinating personal account and historical narrative of the birth and development of a screening program for Duchenne Muscular Dystrophy in Germany, beginning 40 years ago. As the author notes, approval of an institutional review board or ethics committee was not required for this type of scientific investigation in one's field at the time this program was begun, but we have removed all personal data from any of the materials presented in here in order to conform to current concepts of ethical publication. This article is about the screening of 528,410, mostly 4-6-week-old, boys in Germany between 1977 and 2011 for high levels of creatine kinase (CK) to identify those with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). During these 34 years of infant screening, 147 boys with confirmed, probable, and possible DMD (incidence 1:3,600 male births) and 33 boys with confirmed, probable, and possible BMD (incidence 1:15,500 male births) were found. Research reports about DMD were sent to families and pediatricians participating in the screening, and, on request, to families and scientists everywhere. It is hoped that screening programs used as the basis for future therapies will be able to modify the natural history of boys with DMD. New dystrophin mutations will continue to occur, necessitating screening and early therapy. Abstract Submitted for Presentation at the 10th International Society for Neonatal Screening-Asia Pacific Regional Meeting, August 2017, Ulaanbataar, Mongolia. Muscle Nerve 57: 185-188, 2018.

Creatine kinase in human erythrocytes: A genetic anomaly reveals presence of soluble brain-type isoform.

For maintaining energy homeostasis, creatine kinase (CK) is present at elevated levels in tissues with high and/or fluctuating energy requirements such as muscle, brain, and epithelia, while there is very few CK, if any, in peripheral blood cells. However, an ectopic expression of brain-type creatine kinase (BCK) has been reported for platelets and leukocytes in an autosomal dominant inherited anomaly named CKBE. Here we investigated CK in erythrocytes of CKBE individuals from eight unrelated families. The data revealed a varying but significant increase of CK activity in CKBE individuals as compared to controls, reaching an almost 800-fold increase in two CKBE individuals which also had increased erythrocyte creatine. Immunoblotting with highly specific antibodies confirmed that the expressed CK isoform is BCK. Cell fractionation evidenced soluble BCK, suggesting cytosolic and not membrane localization of erythrocyte CK as reported earlier. These results are discussed in the context of putative CK energy buffering and transfer functions in red blood cells.

High levels of brain-type creatine kinase activity in human platelets and leukocytes: a genetic anomaly with autosomal dominant inheritance.

The ectopic expression in peripheral blood cells of the brain-type creatine kinase (CKB) is an autosomal dominant inherited anomaly named CKBE (MIM ID 123270). Here, we characterized the CK activity in serum, platelets (PLT) and leukocytes (WBC) of 22 probands (from 8 unrelated families) and 10 controls. CK activity was measured by standard UV-photometry. Expression of the CKB gene was analyzed by real-time PCR and Western blotting. DNA sequencing including bisulfite treatment was used for molecular analysis of the CKB gene. Serum CK levels were comparable between probands and controls. CKBE probands revealed significantly higher CK activity in PLT (3.7 ± 2.7 versus 179.2 ± 83.0 U/10(12) PLT; p<0.001) and WBC (0.4 ± 0.3 versus 2.6 ± 2.1 U/10(9) WBC; p=0.004). Inhibitory anti-CKM antibodies did not affect CK activity indicating that the CK activity is generated exclusively by the CK-BB isoenzyme. CKB mRNA and protein levels were significantly higher in PLT and WBC from probands compared to controls. Re-sequencing of the entire CKB gene and methylation analysis of a CpG island revealed no alteration in CKBE probands. The genetic basis of CKBE remains unclear, however, we propose that a de-methylated CKB gene is inherited that leads to high CKB expression levels in myeloic precursor cells in the bone marrow.

Identifying Non-Duchenne Muscular Dystrophy-Positive and False Negative Results in Prior Duchenne Muscular Dystrophy Newborn Screening Programs: A Review.

IMPORTANCE: Duchenne muscular dystrophy (DMD) is a candidate for the recommended universal screening panel based on evidence that early corticosteroid treatment improves outcomes and on new genetic therapies that require early diagnosis for effectiveness. Elevated creatine kinase levels in the neonatal period are the initial screening marker in DMD newborn screening programs but is found in inherited muscle disorders other than DMD. Data are needed to inform protocols for future screening and follow-up testing and care in these patients. OBJECTIVES: To review non-DMD muscle disorders identified by prior DMD screening programs and to investigate whether these programs failed to identify patients later diagnosed as having DMD (false-negative findings). EVIDENCE REVIEW: Since 1975, 10 DMD newborn screening programs have provided opportunities to study screening protocols, outcomes, and parental responses. These programs used elevated creatine kinase levels in dried blood spots for the initial screening, with the diagnosis of DMD based on findings of clinical follow-up, muscle biopsy, or direct mutational testing of the DMD gene. Literature regarding these prior programs was reviewed in PubMed, and the programs were discussed directly with the directors when possible to identify diagnoses of non-DMD disorders and false negative results from 1975 to July 12, 2015. Data were collected from screening programs, which were active between 1975 and December 2011. Data were analyzed from March 26, 2015, to August 24, 2015. FINDINGS: The 10 screening programs screened more than 1.8 million newborns between 1975 and 2011, and 344 were diagnosed with DMD. Of those screened, the majority were boys. Across all programs, 80 patients had positive results for non-DMD disorders, including Becker muscular dystrophy and forms of limb-girdle and congenital muscular dystrophies, and 21 patients had false-negative findings for DMD. CONCLUSIONS AND RELEVANCE: Screening for DMD will result in identification of other muscle diseases. Future screening protocols should include infants of both sexes and include follow-up testing algorithms to evaluate patients who do not have DMD gene mutations but may have another muscle disorder associated with elevated neonatal creatine kinase levels. These programs will need to be aware that false-negative results are a possibility.

Report on a Round Table Conference in Monaco on 17th and 18th January, 2004.

Duchenne Parent Project France and the Association Monegasque Contre les Myopathies invited 35 scientists and representatives of Duchenne parent groups for this Round-Table Conference in Monaco. Two scientific approaches towards the treatment of Duchenne muscular dystrophy were discussed. The following text is not a scientific report for experts but was written for the families with Duchenne boys in January and February 2004. Some of the experiments are described in greater detail, because this report should make it clear that in spite of the incredible complexity of the human genetic structure, new experimental techniques and the skill of the scientists make it possible to manipulate the information of the very large dystrophin gene without interfering with the other about 25,000 to 30,000 genes in every cell of a Duchenne boy.