Variability of multisystemic features in myotonic dystrophy type 1--lessons from Serbian registry.

BACKGROUND: Myotonic dystrophy type 1 (DM1) is a rare disease. Creating registry for such a disease is of outstanding importance since it provides us with a full spectrum of the disorder. AIM: To assess variability of different multisystemic features in a large cohort of patients with DM1. PATIENTS AND METHOD: Data from the Serbian registry for myotonic dystrophies were used in the study. Final number of included DM1 subjects was 275. RESULTS: Registry included 53.8% of male patients. Age at enrollment was 47.2 ± 9.9 years, mean disease duration 20.4 ± 9.9 years, and mean CTG repeats number 598.3 ± 269.8.Progression of muscle weakness was pretty slow, slower in proximal than distal muscles, and slower in arms than in legs. Severe ECG abnormality was found in 25.0% of patients and pacemaker was implanted in 9.5%. Lens opacities were observed in 83.5% of DM1 patients and 35.3% had ocular hypotony. Metabolic disturbances were very common, while 19.5% of patients had hypokalemia and 37.8% hypochloremia. Sterility was found in 20.5% of males and 4.1% of females. Cholelithiasis was found in 36.4% of patients and constipation in 29.9%. CONCLUSIONS: We defined the most common characteristics of our DM1 patients and observed some treatable symptoms that have been neglected previously. Certain findings deserve further investigations in terms of their causes and consequences. Besides this, presented data analysis directs us to make further improvements of the registry.

Metabolic syndrome in patients with myotonic dystrophy type 1.

INTRODUCTION: The aim of this study was to assess the frequency and features of metabolic syndrome (MetS) in myotonic dystrophy type 1 (DM1). METHODS: We studied 66 DM1 patients (50% men, aged 41.9 ± 10.5 years, disease duration of 19.3 ± 8.6 years). New worldwide consensus criteria for MetS from 2009 were used. RESULTS: Components of MetS were present at the following frequencies: hypertriglyceridemia 67%; low HDL cholesterol 35%; hypertension 18%; central obesity 14%; and hyperglycemia 9%. MetS was present in 11 (17%) patients. The presence of MetS was not associated with patients' gender, age, disease severity, disease duration, or CTG repeat length (P > 0.05). Patients with MetS had significantly lower total SF-36 scores as a measure of quality of life in comparison to patients without MetS (P < 0.05). CONCLUSION: Although certain components of MetS were very frequent in patients with DM1, only 17% met the criteria for MetS.

C9orf72 expansion as a possible genetic cause of Huntington disease phenocopy syndrome.

Huntington disease (HD), the most common inherited cause of chorea, is an autosomal dominant disorder, caused by an expanded trinucleotide CAG repeat (>39) in the HTT gene on chromosome 4p16.3. Among patients diagnosed as HD solely on clinical grounds, a certain number was negative on genetic testing for HD. Therefore, HD-like disorders comprised a number of genetic causes of chorea, that may be indistinguishable from HD (e.g. HD phenocopy syndrome). Recent data suggested that the C9orf72 expansion may be the most common genetic cause of HD phenocopy presentations. In continuation with this observation, we analyzed a small cohort of 39 patients with HD phenocopy syndrome and detected the C9orf72 expansion in one female patient (2.6%) with two-year lasting mild generalized chorea and severe oro-bucco-lingual dyskinesia, who complained on forgetfullness (neuropsychological testing revealed dysexecutive syndrome with preserved episodic memory and recognition), unexplainable fears and increased appetite. Our results confirmed a possible role of the C9orf72 expansion in the genetic background of HD phenocopy syndrome.

De novo mutation in the GNAL gene causing seemingly sporadic dystonia in a Serbian patient.

BACKGROUND: Mutations in GNAL (DYT25) have recently been established as the first confirmed cause of focal or segmental adult-onset dystonia. Mutation carriers show craniocervical involvement; however, the GNAL mutational and phenotypic spectrum remain to be further characterized, and guidelines for diagnostic testing need to be established. METHODS: The authors used Sanger sequencing to test for changes in the GNAL coding or splice-site regions in 236 Serbian patients suffering from isolated dystonia with craniocervical involvement. RESULTS: One novel likely pathogenic substitution (c.1061T>C; p.Val354Ala) in GNAL was detected in a sporadic cervical dystonia patient (mutation frequency: 0.4%). This mutation was not present in the DNA of either parent, despite confirmed parentage. CONCLUSIONS: This is the first report of a de novo GNAL mutation causing genetically proven, seemingly sporadic DYT25 dystonia. Our finding highlights the importance of genetic testing for GNAL mutations in establishing the molecular diagnosis even for patients with a negative family history.

Transcranial sonography in patients with myotonic dystrophy type 1.

INTRODUCTION: In this study we analyzed transcranial sonography (TCS) in patients with myotonic dystrophy type 1 (DM1). METHODS: This cross-sectional study included 66 DM1 patients and 55 matched healthy controls (HCs). Echogenicity of the brainstem raphe (BR) and substantia nigra (SN) and third ventricle width (DTV) were assessed by TCS. RESULTS: BR hypoechogenicity was more common in DM1 patients than in HCs (37.7% vs. 7.8%, P < 0.01). Patients with depression or fatigue were more likely to have BR hypoechogenicity (80.0% vs. 29.4%, P < 0.01 and 51.9% vs. 24.2%, P < 0.05, respectively). Both hypoechogenicity and hyperechogenicity of SN were more frequent in DM1 patients than in controls (26.2% vs. 10.9% and 13.1% vs. 1.8%, respectively, P < 0.01). DTV was increased in DM1 patients compared with HCs (6.0 ± 1.4 vs. 4.9 ± 0.9 mm, P < 0.01). CONCLUSION: TCS can offer new insight into structural changes of several cerebral areas in patients with DM1.