Charlotte Thiels

Cardiolipin and monolysocardiolipin analysis in fibroblasts, lymphocytes, and tissues using high-performance liquid chromatography-mass spectrometry as a diagnostic test for Barth syndrome

Barth syndrome (BTHS) is an X-linked recessive disorder caused by mutations in the tafazzin (or TAZ) gene and is clinically characterized by (cardio)myopathy, neutropenia, and growth abnormalities. Biochemical abnormalities include decreased levels of the mitochondrial phospholipid cardiolipin, increased levels of monolysocardiolipin, and a lower degree of unsaturation of the (monolyso)cardiolipin acyl chains. Diagnostic testing for BTHS is routinely performed by TAZ gene sequencing, and recently a BTHS screening method in bloodspots has been developed, but both methods have important limitations. Because a validated confirmatory method is not yet available, we set up and validated a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method for BTHS in cultured fibroblasts, lymphocytes, and skeletal muscle based on cardiolipin, monolysocardiolipin, and the monolysocardiolipin/cardiolipin ratio. In addition, we performed retrospective analysis of 121 muscle samples of patients with myopathy of which mitochondrial origin was presumed, and we identified one patient with cardiolipin abnormalities similar to BTHS patients. Molecular analysis revealed a bona fide mutation in the TAZ gene. We conclude that (monolyso)cardiolipin analysis by HPLC-MS not only is a powerful tool to diagnose patients with clinical signs and symptoms of BTHS but also should be used in patients suffering from mitochondrial myopathies with unknown etiology.

Prognostic relevance of MOG antibodies in children with an acquired demyelinating syndrome

Objective: To assess the prognostic value of MOG antibodies (abs) in the differential diagnosis of acquired demyelinating syndromes (ADS). Methods: Clinical course, MRI, MOG-abs, AQP4-abs, and CSF cells and oligoclonal bands (OCB) in children with ADS and 24 months of follow-up were reviewed in this observational prospective multicenter hospital-based study. Results: Two hundred ten children with ADS were included and diagnosed with acute disseminated encephalomyelitis (ADEM) (n = 60), neuromyelitis optica spectrum disorder (NMOSD) (n = 12), clinically isolated syndrome (CIS) (n = 101), and multiple sclerosis (MS) (n = 37) after the first episode. MOG-abs were predominantly found in ADEM (57%) and less frequently in NMOSD (25%), CIS (25%), or MS (8%). Increased MOG-ab titers were associated with younger age (p = 0.0001), diagnosis of ADEM (p = 0.005), increased CSF cell counts (p = 0.011), and negative OCB (p = 0.012). At 24-month follow-up, 96 children had no further relapses. Thirty-five children developed recurrent non-MS episodes (63% MOG-, 17% AQP4-abs at onset). Seventy-nine children developed MS (4% MOG-abs at onset). Recurrent non-MS episodes were associated with high MOG-ab titers (p = 0.0003) and older age at onset (p = 0.024). MS was predicted by MS-like MRI (p < 0.0001) and OCB (p = 0.007). An MOG-ab cutoff titer ≥1:1,280 predicted a non-MS course with a sensitivity of 47% and a specificity of 100% and a recurrent non-MS course with a sensitivity of 46% and a specificity of 86%. Conclusions: Our results show that the presence of MOG-abs strongly depends on the age at disease onset and that high MOG-ab titers were associated with a recurrent non-MS disease course.

Outcome of patients with classical infantile pompe disease receiving enzyme replacement therapy in Germany

PURPOSE Enzyme replacement therapy (ERT) has been shown to improve outcome in classical infantile Pompe disease. The purpose of this study was to assess mortality, morbidity, and shortcomings of ERT in a larger cohort of patients treated outside clinical trials. To accomplish this, we retrospectively analyzed the data of all 23 subjects with classical infantile Pompe disease having started ERT in Germany between January 2003 and December 2010. RESULTS Ten patients (43%) deceased and four others (17%) became ventilator dependent. Seven infants (30.5%) made no motor progress at all, while seven (30.5%) achieved free sitting, and nine (39%) gained free walking. Besides all the seven patients (100%) attaining no improvement of motor functions, four out of the seven (57%) achieving to sit without support, and three out of the nine (33%) being able to walk independently, secondarily deteriorated, and died or became ventilator dependent. Sustained reduction of systolic function despite reversal of cardiac hypertrophy (n = 3), gastroesophageal reflux (n = 5), swallowing difficulties or failure to thrive (n = 11), recurrent pneumonias (n = 14), port system complications (n = 4), anesthesia-related incidents (n = 2), severe allergic reactions (n = 6), hearing loss (n = 3), and orthopedic deformities (n = 4) were problems frequently encountered. CONCLUSION Although this study has important shortcomings due to its retrospective nature and because important variables potentially influencing outcome were not available for a substantial amount of patients, these data suggest that classical infantile Pompe disease still remains a life-threatening condition associated with high morbidity and often dismal prognosis. Currently, a relevant number of patients do not benefit definitely from ERT.

Extreme phenotypic variability in a German family with X-linked myotubular myopathy associated with E404K mutation in MTM1

X-linked myotubular myopathy (XLMTM) is a congenital muscle disorder caused by mutations in the MTM1 gene. Affected males usually present at birth with severe hypotonia and respiratory insufficiency, and most of them die within the first few years of life. We report here on a 68-year-old patient with a very mild form of the disease who was diagnosed after his grandson showed muscular weakness and respiratory problems at birth. The E404K mutation in the MTM1 gene was found in both patients. To our knowledge, this grandfather is one of the oldest and most mildly affected known patients with an MTM1 mutation to date. Thus, this family represents a remarkable phenotypic variation of XLMTM ranging from a congenital to a mild adult form.

Improved diagnostics lead to identification of three new patients with congenital disorder of glycosylation-Ip†

Congenital disorders of glycosylation (CDG) comprise a clinically and biochemically heterogeneous group of monogenetic‐inherited, multisystemic diseases that affect the biosynthesis of N‐ and/or O‐glycans linked to glycoconjugates. Recently, we identified the first patient with a defect in the cytosolic‐orientated GDP‐mannose:Man3‐4GlcNAc2‐PP‐dolichol alpha‐1,2‐mannosyltransferase (ALG11), who presented an accumulation of shortened dolichol‐linked oligosaccharides leading to CDG‐Ip (ALG11‐CDG). Here we describe an improved metabolic labeling method that allowed the identification of three new CDG‐Ip cases that were missed so far in routine diagnostics. Although all CDG‐Ip patients carry different mutations in the ALG11 gene, they share a variety of clinical syndromes like an unremarkable prenatal period followed by developmental delay, psychomotor, and mental retardation, strabismus convergens and seizures occurring in the first year of life. Hum Mutat 33:485–487, 2012.

Long Survival in Leigh Syndrome: New Cases and Review of Literature

Leigh syndrome (MIM 25600), also known as infantile subacute necrotizing encephalomyelopathy, is a neurodegenerative disorder with characteristic bilateral symmetric lesions in basal ganglia and subcortical brain regions. It is commonly associated with systemic cytochrome c oxidase (COX) deficiency and mutations in the SURF1 gene (MIM 185620), encoding a putative assembly or maintenance factor of COX. The clinical course is dominated by neurodevelopmental regression, brain stem, and basal ganglia involvement (e.g., dystonia, apnea) with death often occurring before the age of 10 years. Herein, we present three sisters carrying a previously reported homozygous SURF1 mutation (c.868_869insT) that is predicted to result in a truncated protein with loss of function. Our patients show heterogeneous clinical findings with different distribution patterns of metabolic lesions in brain magnetic resonance imaging (MRI) as well as a Chiari malformation with hydrocephalus in one patient. However, all three siblings show an unusual long survival (12 years and>16 years). COX activity was not detectable in one patient and strongly reduced in the other two. We discuss these findings with respect to a review of the literature. A total of 15 additional patients with survival>14 years have been reported so far. Overall, no clear genotype-phenotype correlations are detectable among these patients.

Early-onset leukoencephalopathy due to a homozygous missense mutation in the DARS2 gene.

Mutations in the DARS2 gene are known to cause leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL), a rare autosomal recessive neurological disorder. It was originally described as juvenile-onset slowly progressive ataxia and spasticity, but recent reports suggest a broader clinical spectrum. Most patients were found to carry compound heterozygous DARS2 mutations, and only very few patients with homozygous mutations have been described so far. We present here an 8-month-old boy carrying a homozygous missense mutation in DARS2 who clinically showed severe neurological deterioration after a respiratory tract infection, followed by an almost complete remission of symptoms. This report further extends the knowledge about the clinical and molecular genetic spectrum of LBSL.

Cannabinoids for Treatment of Dystonia in Huntington’s Disease

BACKGROUND Motor symptoms in Huntingtons disease (HD) are heterogeneous with dystonia being described as a symptom with a very high prevalence not only in juvenile cases. OBJECTIVE Treatment options for dystonia are limited. Cannabinoids have been described as a potential treatment for patients with dystonia of a different origin. Here, we present early onset HD patients with a marked improvement of motor symptoms mainly due to alleviation of dystonia due to treatment with cannabinoids. In addition we review the current literature concerning the use of cannabinoids in HD. METHOD The Unified Huntingtons Disease Rating Scale (UHDRS) motor score, including a chorea and dystonia subscore, was conducted before and after the start of cannabinoids in seven patients without any other changes in medication. RESULTS The UHDRS motor score and the dystonia subscore (±SD) improved from 70.9 (25.5) to 60.6 (26.9) with a mean change of 10.3 [95% CI 6.0-14.6] and from 12.3 (4.0) to 8.0 (3.6) with a mean change of 4.3 [95% CI 2.3-6.3], respectively (both p = 0.018). CONCLUSION Improvement of motor symptoms, mainly dystonia, led to several relevant improvements from a global clinical perspective such as improvement of care, gait and fine motor skills and weight gain. Moreover, we observed changes in behavior with less irritability and apathy, as well as less hypersalivation in some cases.

CNS findings in congenital muscular dystrophy 1A (with laminin alpha-2-deficiency)

Congenital muscular dystrophy (MDC) is a group of rare hereditary myopathies with an early onset of progressive muscle weakness and dystrophic changes as evidenced by muscle biopsy. Some forms are associated with severe malformations of the brain. This study presented 2 pediatric patients with genetically diagnosed congenital muscular dystrophy 1A. The patients exhibited a typical combination of muscular hypotonia, joint contractures and elevated creatine kinase levels. Characteristic white matter lesions were not present in an early MRI scan of one patient, but could be detected at the age of 18 months. The second patient showed both severe white and grey matter abnormalities (pachy microgyria) in the MRI scan. In both cases, MRI findings did not correlate with the mental development of the patients.

Muscular hypotonia, joint contractures and elevated creatin kinase level as main symptoms for Congenital muscular dystrophy 1A (MDC 1A/congenital muscular dystrophy with laminin α 2 (merosin) deficiency)

Introduction: congenital muscular dystrophies (MDC) are hereditary myopathies characterized by congenital muscular hypotonia, delayed motor development and early onset of progressive muscle weakness. Dystrophic patterns are found in muscular biopsy. Some forms are associated with affections of the brain or eyes. Incidental rate is ca. 2.5–4.5×(10–5). The congenital muscular dystrophy with laminin α 2 -deficiency (MDC1A) counts ca. 30 to 40% of all MDC in Europe. A defect of laminin α 2 affects primarily the basement membrane of the muscular cell. Case report 1: We describe a girl with muscular hypotonia, delayed motor development, proximal muscular weakness, lacking of head control, joint conctractures and absence of muscular reflexes at the age of 10 weeks. Creatine kinase was markedly elevated (3510U/l). Echocardiography and electrocardiogram were normal. The MRI of brain was normal, muscle MRI showed substantial edematous changes. Active dystrophic patterns were found in muscular biopsy. Immunohistochemical analysis of laminin α-2 showed absence of expression. Analysis of the laminin α 2-gene on chromosome 6q2 could detect a homozygous mutation (Exon 36: IVS36+1G>A), which was heterozygous found at the consanguinous parents. Now 9 month old, the girls grows well, no significant motor development is seen, one respiratory infection due to RS-virus with need of oxygene supply. Case report 2: Second patient showed a postnatal muscular hypotonia without breathing oder feeding problems. At age of 5 months no significant motor development, proximal muscular weakness, joint contractures und no muscular reflexes. Elevation of creatine kinase was significant (2604U/l). Normal echocardiography an electrocardiogram. In the laminin α 2 -gene 2 different mutations Heterozygotie (Exon 32: c.4645C>T p,ARg1549X, Exon 4: c.498G>A p,Trp166X) were found, each of came from 1 parent, who were not consanguinous. Now 15 month old minimal progress in motoric function can be seen (turn from supine position to the side is possible, playing with toys in supine position), no problems concerning respiration and as far no delay in speech an cognitive development. In comparison to the presented girl seems the muscular fonction to be slightly better. Conclusion: We present 2 children with genetically diagnosed congenital muscular dystrophy 1A with typical combination of muscular hypotonia, joint contractures and elevates creatin kinase level.