Involvement Of Facial Muscles Research Articles

Mild Clinical Features and Histopathologically Atypical Cores in Two Korean Families with Central Core Disease HarboringRYR1Mutations at the C-Terminal Region

BackgroundCentral core disease (CCD) is a congenital myopathy characterized by distinctive cores in muscle fibers. Mutations in the gene encoding ryanodine receptor 1 (RYR1) have been identified in most CCD patients.Case ReportTwo unrelated patients presented with slowly progressive or nonprogressive proximal muscle weakness since childhood. Their family history revealed some members with the same clinical problem. Histological analysis of muscle biopsy samples revealed numerous peripheral cores in the muscle fibers. RYR1 sequence analysis disclosed a novel mutation in exon 101 (c.14590T>C) and confirmed a previously reported mutation in exon 102 (c.14678G>A).ConclusionsWe report herein two families with CCD in whom missense mutations at the C-terminal of RYR1 were identified. Although it has been accepted that such mutations are usually associated with a severe clinical phenotype and clearly demarcated central cores, our patients exhibited a mild clinical phenotype without facial muscle involvement and skeletal deformities, and atypical cores in their muscle biopsy specimens.

Quantitative Electromyography of the Frontalis Muscle

Identification of abnormal motor unit potentials (MUP), in particular those caused by myopathic processes, is generally difficult in facial muscles because the MUPs are already low in amplitude and short in duration. Therefore, quantitative measures for the limits of abnormality are needed more frequently for these muscles, especially for the pathological processes predominantly affecting the craniofacial area. In this study, we aimed to determine some quantitative values that may help us to differentiate "myogenic" and "neurogenic" processes in periocular muscles. The frontalis muscle was examined unilaterally with multi-MUP and interference pattern analyses in 32 normal subjects, 31 patients with different types of myopathy, and 13 patients with facial palsy. Abnormality limits were calculated by using five previously suggested methods, two of which were based on group means and the other three on determining the outlier values. The sensitivity and specificity of multi-MUP and interference pattern parameters in discriminating abnormal findings by using these different methods were analyzed. Statistically significant differences for all MUP parameters, except for the frequency, was found between the groups (P < 0.001). Motor unit potential duration, size index, and amplitude were the most valuable parameters for distinguishing the individual abnormalities. However, their discriminating power was higher for neuropathies than for myopathies. Interference pattern analysis was found not to have any superior sensitivity to MUP analysis. In this study, the outlier analysis that depends on the 5th to 95th percentile limits of the pooled data provided the best power for the discrimination of both neuropathies and myopathies from normal subjects. Multi-MUP analysis seems to be helpful in differentiating the patients with neurogenic and-to a lesser extent-myogenic facial muscle involvement.

P.16.5 Anxiety is responsible for altered sleep quality in Facio-Scapulo-Humeral Muscular Dystrophy (FSHD)

FSHD is one of the most frequent forms of muscular dystrophy characterized by an early involvement of facial and scapular muscles with eventual spreading to pelvic and lower limb muscles. Few studies have been dedicated to sleep disorders in FHSD. Our objective was to explore subjective sleep quality in FSHD patients. Adults with genetically proven FSHD were included in the study. They were compared to a control group of subjects with no myopathy, no past neurological disease nor instable chronic disease history. The Pittsburgh sleep quality index (PSQI), the Epworth sleepiness scale (ESS), the clinical severity scale (CSS), the fatigue severity scale and the hospital anxiety and depression scale were used to evaluate the severity of the sleep disorder, the subjective sleep quality, the prevalence of daytime sleepiness, the anxiety and the depression in patients and controls. Pulmonary function and MRC score were also assessed. Mann Withney test, Spearman correlation and Fisher test were used for the statistics analysis. 22 FSHD and 36 controls were included in the study. Both groups were similar as for age, sexe, body mass index and respiratory support. 50% of FSHD patients presented with vital capacity p p = 0.04). The latter was also correlated with depression, fatigue and bad dreams. Surprisingly, we noticed a negative correlation between ESS and CSS: the loss of activity in severe patients could result in harmony with sleep needs. FSHD patients have altered subjective sleep quality as compared with control population. Anxiety mainly accounts for this, while severity of the disease and respiratory involvement do not affect it.

The Autosomal Dominant Facioscapuloperoneal Muscular Dystrophy with 4q35 Chromosomal Deletion in Two Russian Families

We give the description of the pattern of muscle affections in two autosomal dominant 4q35-linked facioscapuloperoneal muscular dystrophy (FSPMD) families in which the patients were re-examined by V.K. in 24 - 28 and 35 - 37 years after their first examination. The disease started with initial involvement of facial and shoulder girdle muscles and in some time later of the peroneal group (anterior tibial) of muscles became involved. However, in two probands the dystrophic process gradually extended to the thighs (posterior group of muscles, namely), pelvic girdle (gluteus maximus muscles, namely) and the upper arm (biceps brachii muscles were slightly affected) and in three their relatives with clinical facioscapuloperoneal (FSP) phenotype the severe involvement of some posterior thigh muscles during MRI study was revealed. In this connection, the term “facioscapulolimb muscular dystrophy, type 2 (FSLD2), a descending type with a “jump” with initial FSP phenotype” would be more correct instead of the name facioscapuloperoneal muscular dystrophy. The FSP phenotype constitutes merely a stage in the development of FSLD2. The CT and MRI pattern of muscle involvement does not fully correlate with clinical pattern of muscle affection. We suppose that classical AD FSPMD is an independent clinical form which is different from the classical FSHD although both of them are connected with 4q35 chromosomal deletion.

Rare Blast Phase (BP) Phenotypes of Chronic Myeloid Leukemia (CML)

AbstractAbstract 4434Approximately 65% of patients (pts) with CML BP exhibit a myeloid phenotype, 30% a lymphoid, and 5% of cases exhibit other phenotypes. The vast majority of lymphoid BP cases are of B-cell origin. Other phenotypes of CML BP are very infrequent and poorly characterized. To evaluate the incidence and outcome of unusual BP phenotypes, we reviewed 1143 pts with CML BP diagnosed and treated at M.D. Anderson Cancer Center between November 1973 and February 2012. Thirteen (1%) pts had non-B-cell/non-myeloid CML BP: 8 pts with T-cell differentiation (T-BP) (including 4 pts with biphenotypic T-cell/myeloid), 2 pts with basophilic (B-BP), and 3 pts with megakaryoblastic phenotype (M-BP) (Table 1). Five pts presented initially in BP, whereas 7 other cases evolved to BP from chronic phase (CP) and 1 pt from accelerated phase (AP). The median time from diagnosis to transformation was 15.2 months (mos) (range, 0–103). The median age was 50 years (range, 21–74), median WBC count at presentation 40.2×109/L (range, 2.6–236), hemoglobin 10.7 g/dL (range, 7.1–13.6), platelet count 171×109/L (range, 17–383), peripheral blood blasts 9% (range, 0–100), and bone marrow blasts 20% (range, 0–88). Nine (69%) pts developed extramedullary disease: 4 with lymphadenopathy (LAN), 1 with LAN and mediastinal mass, 1 with pericardial tamponade and mediastinal mass, 1 with central nervous system disease, 1 with facial muscle involvement and 1 with splenomegaly, LAN, and granulocytic sarcoma of the breast. Four pts expressed a b2a2 BCR-ABL1 transcript (p210), whereas 3 pts expressed b3a2 (p210), 3 expressed e1a2 (p190), 2 expressed b2a2+b3a2 (p210), and 1 expressed an e13b2+e14a2 (p210) transcript at transformation that switched to e1a2 (p190) during dasatinib (DAS) therapy. Median number of treatments received prior to BP was 2 (range, 1 to 12): 6 pts received interferon (IFN), 5 imatinib (IMA), 3 allogenetic stem cell transplant (ASCT), 3 Ara-C, 1 DAS and 1 hyper-CVAD (HCVAD). Initial therapy consisted of HCVAD (n=4, combined with IMA 600 mg/d in 1 pt and with DAS 70 mg/d in 1 pt), VAD (n=1), nilotinib 400 mg twice daily (n=1), DAS 50 mg twice daily (n=1), troxicitabine (n=1), gemtuzumab (n=1), idarubicin (IDA) and ara-C (n=3; 1 with IMA 600 mg/d and 1 with IMA 400 mg/d), and ara-C (n=1). Four pts responded: 3 with chemotherapy and IMA, achieving a complete cytogenetic response (CCyR) that lasted 22, 26 and 79 mos, respectively; 1 pt achieved a major molecular response (MMR) after receiving gemtuzumab followed by haploidenticial SCT, lasting for 24 mos. Median duration of response was 25 mos (range, 22–79). Subsequent therapy consisted of a tyrosine kinase inhibitor (TKI) in 6 out of 13 pts. Two pts treated with DAS at 140 mg/d and 70 mg twice daily achieved a CCyR and 1 pt achieved MMR on DAS 140 mg/d. Of the 7 pts treated with DAS, 2 had BCR-ABL1 mutations: 1 carried K271R, Y232C/K271R, and M343Y/K271R prior to DAS, then acquired V299L and F317I on DAS, while the other pt carried Y264S prior to DAS, then developed V299L on DAS. After a median follow up of 4.2 years (range, 0.2 to 14.4), 4/13 (30%) pts are alive: 1 in MMR on IMA 400 mg/d, 1 in complete molecular response (CMR) on DAS 100 mg/d, 1 not in remission (non-compliance to DAS 140 mg/d), and 1 currently receiving HCVAD and DAS. By phenotype, 5/8 pts with T-BP responded to TKIs: 1 CMR, 1 CCyR, 1 MMR, 1 partial cytogenetic response (PCyR) and 1 hematologic response (HR); 2/3 pts with M-BP responded: 1 CCyR and 1 CHR. None of the B-BP pts responded. In conclusion, non-B-cell/non-myeloid CML BP occurs in 1% of pts with CML, frequently infiltrates extramedullary sites, and exhibits high resistance to conventional chemotherapy. Long-term responses can be achieved with ABL1 TKIs (preferably in combination with chemotherapy), which can be used as a bridge to allogeneic SCT. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Interpreting arterial blood gases

Objective This study explores the use of quantitative data on strength and fatigability of orofacial muscles in patients with facioscapulohumeral muscular dystrophy (FSHD) and assesses the frequency of swallowing and communication difficulties and their relationship to orofacial muscle involvement. Methods We included 43 patients with FSHD and 35 healthy controls and used the Iowa Oral Performance Instrument (IOPI) to obtain quantitative measurements of strength and endurance of lip compression, cheek (buccodental) compression, and tongue elevation. For the assessment of swallowing and communication difficulties, we used the dysphagia-specific quality of life (SWAL-QOL) and Communicative Participation Item Bank questionnaires. Results Cheek compression strength was reduced in patients with FSHD compared to healthy controls. Dysphagia and difficulty with verbal communication were reported by 25% and 35% of patients, respectively, and correlated to cheek compression strength and endurance and to anterior tongue elevation endurance. Prolonged cheek compression or anterior tongue elevation endurance (decreased fatigability) made swallowing or speech problems less likely to occur. Conclusion Cheek compression strength is the most sensitive IOPI measure for orofacial weakness in FSHD. Orofacial weakness contributes to dysphagia and speech difficulties in FSHD, which are both common, though generally mild. Higher endurance of orofacial muscles was associated with a lower chance of dysphagia or speech problems. More research is required for further refinement of the pattern of facial muscle involvement in FSHD and to provide new insights for improvement of speech and language therapy.

Atypical onset in a series of 122 cases with FacioScapuloHumeral Muscular Dystrophy

IntroductionFacioScapuloHumeral Muscular Dystrophy (FSHD), a disease linked to a heterozygous D4Z4 deletion on chromosome 4q35, typically starts with shoulder-girdle and facial muscle involvement. Atypical presentations have occasionally been reported, but their frequency has still not been defined. Patients and methodsWe studied the occurrence rate of FSHD with atypical onset in 122 symptomatic subjects from 76 unrelated families with genetically confirmed FSHD. These 75 males and 47 females, with a mean age of 49 years (range: 11–85), had a mean EcoRI fragment of 25kb (range: 11–38). ResultsTypical shoulder-girdle or facial weakness at onset was reported by 88 patients (72%). Unusual presentations included: foot drop in 16 (13%) and proximal lower limb weakness in eight patients (7%). Two cases at onset manifested quite atypical, apparently non-FSHD-related syndromes: a 42-year-old woman presented with infantile epilepsy and a 41-year-old man with myoglobinuria. In the latter patient, DNA analysis detected a 4q35 deletion associated to an heterozygous CAPN3 mutation. ConclusionFSHD presentation with foot drop or lower limb proximal weakness appeared to be more frequent than expected. This type of weakness at onset has to be considered premature, but still representative of disease-related muscle involvement. Quite atypical onset appears very rare and calls for further investigation on non-FSHD-related etiology.

Hemifacial spasm can be the presenting symptom of a fourth ventricle tumour. A short case-illustrated review and pathogenetic considerations

In this short case-illustrated review we aimed to analyse the possible nuances of hemifacial spasm (HFS) as the presenting symptom of a tumour of the fourth ventricle. The issue is remarkable since HFS can be secondary to a fourth ventricle tumour, even when no other neurological signs are reported. In addition, the possible presentation with only upper facial muscle involvement, as in the presented case, can be deceitful because this is characteristic of the benign and much more frequent "typical" form. Based on our intra-operative data and on the previously reported cases, we think that pathogenesis could be referable to the facial nerve nucleus involvement and that clinical nuances could be related to the specific somatotropy of the nucleus under the fourth ventricle floor that, as in our case, can be infiltrated by tumour. Resolution of the disorder can usually be obtained after the complete resection of the tumour that in the reported case resulted a subependymoma (WHO grade I), so far never described in literature associated with HFS.

中枢神経症状, 顔面筋罹患, CPK高値, 軽度筋原性病理像を呈した先天性ミオパチーの1例 福山型先天性筋ジストロフィーの亜型

中枢神経症状, 顔面筋罹患, CPK高値, 軽度筋原性病理像を呈した先天性ミオパチーの1例 福山型先天性筋ジストロフィーの亜型

Limb-Girdle Myasthenia Gravis in a 10-Year-Old Girl

A 10-year-old girl presented with progressive proximal limb muscle weakness without facial, ocular, or bulbar muscle involvement. There was no fatigability or diurnal fluctuation in symptoms. Her weakness worsened with febrile illnesses and recovered with accruing disabilities over a few weeks. Serum creatine kinase levels and muscle biopsy were normal. A significant decrement on repetitive nerve stimulation test and positive response to therapeutic neostigmine challenge test confirmed the diagnosis of limb-girdle myasthenia. She responded well to corticosteroids and thymectomy, demonstrating a likely autoimmune etiology. This case highlights the long-term fluctuations in a case of myasthenia gravis and the need for a high index of suspicion for myasthenia in children presenting with unexplained muscle weakness, even in the absence of typical features such as fatigability, diurnal fluctuation, and oculobulbar weakness.

先天型筋ジストロフィー症 (知能障害, 顔面筋罹患を伴う関節拘縮型先天性筋ジストロフイー症) の生検筋における組織学的, 組織化学的, 及び電子顕微鏡学的研究

先天型筋ジストロフィー症 (知能障害, 顔面筋罹患を伴う関節拘縮型先天性筋ジストロフイー症) の生検筋における組織学的, 組織化学的, 及び電子顕微鏡学的研究

Lobulated fibers in a patient with 46‐year history of limb‐girdle muscle weakness

A 78-year-old man presented with a 46-year history of slowly progressive muscle weakness. He had a past medical history of hypertension but had no familial history of neuromuscular disorders. He first noticed mild muscle weakness affecting his thigh at the age of 32 when he could not keep up with others during mountain climbing. The proximal muscle weakness worsened gradually to difficulty in climbing stairs after the age of 40, and progressed to involve his upper extremities when he could not raise his arms after the age of 50. When he first visited the clinic at the age of 57, physical examination revealed proximaldominant and symmetric muscle weakness with atrophy in his four limbs, pelvic and shoulder girdle muscles. He had no facial muscle involvement or calf muscle hypertrophy. He neither had cardiac nor respiratory abnormality. Serum creatine kinase (CK) level was 1774 (normal <200) IU/L. Electromyography was reported to be myogenic. He was diagnosed by skeletal muscle biopsy and genetic analysis at the age of 58. It became increasingly difficult for him to stand up at the age of 63. He started using a wheelchair but still could walk with a hand-rail at the age of 66. He could drive a car until the age of 74. Since the age of 75, he has been wheelchair-bound.

Is It Always Necessary to Apply Botulinum Toxin into the Lower Facial Muscles in Hemifacial Spasm? A Randomized, Single-Blind, Crossover Trial

Background: Botulinum toxin (BTX) injections are accepted as safe and efficacious in the treatment of hemifacial spasm (HFS), but it is still debated whether BTX treatment of lower facial muscles should be performed or not. Objective: The study aims to evaluate the necessity of BTX administration into lower facial muscles in patients with HFS. Methods: A randomized, single-blind, crossover, clinical trial was conducted. Twenty-three HFS patients were randomly allocated to two different application methods. The patients were administered BTX type A into both the orbicularis oculi and perioral muscles in the first method and BTX type A into the orbicularis oculi but placebo into the perioral muscles in the second method. Subjects were crossed over to the alternate method when they needed BTX injection with a minimum of 3 months’ duration. All the patients underwent both methods with no change in the total dose of BTX. Results: All the patients benefited from BTX treatment regardless of the methods. However, in the patients with severe lower facial muscle involvement, the application of BTX into both orbicularis oculi and lower facial muscles led to better results. Conclusion: Our data suggest that BTX application to lower facial muscles might not be necessary in patients with mild lower facial involvement.

Sleep quality in Facioscapulohumeral muscular dystrophy

To evaluate the subjective sleep quality, the prevalence of daytime sleepiness and the risk of sleep-related upper airways obstruction in patients with genetically proven Facioscapulohumeral muscular dystrophy (FSHD). FSHD is an autosomal dominant myopathy, characterized by an early involvement of facial and scapular muscles with eventual spreading to pelvic and lower limb muscles. Forty-six patients were enrolled, 27 women and 19 men, mean age 43.6+/-14.1 years. Study protocol included: a Clinical Severity Scale (CSS) for FSHD, Pittsburgh Sleep Quality Index (PSQI), Italian version of the Epworth Sleepiness Scale (ESS) and the search for clinical predictors of sleep-related airways obstruction. Twenty-seven patients presented snoring, 12 reported respiratory pauses during sleep. One half (23/46) had PSQI scores above the normal threshold (=5). Correlations were found between the CSS and: the total PSQI score, the components C1 sleep quality, C5 sleep disturbances, C7 daytime dysfunction. Our data support the hypothesis that patients with FSHD have an impaired sleep quality, and that this impairment is directly related to the severity of the disease. A systematic polysomnographic evaluation of these patients will be necessary to confirm the presence of sleep disruption and to clarify its pathogenesis.

Primary craniocervical dystonia presenting as a respiratory emergency

The craniocervical region is frequently affected by dystonia. Facial, lingual, masticatory, and laryngeal muscle involvement is reported in >75% of cases with primary focal/segmental dystonia.1 Symptoms in these cases appear gradually, and there is sufficient time for the patients to seek proper medical attention. Acute dystonic reactions are often secondary to dopaminergic receptor antagonism. Acute laryngeal dystonia has been identified as a life-threatening side effect of classic antipsychotics.2 Herein we describe a patient with primary craniocervical dystonia who presented as a respiratory emergency. A previously healthy 52-year-old man was diagnosed with possible mild asthma after mild breathing difficulties of subacute onset. Following this diagnosis, he was prescribed standard antiasthmatic medication with no success and was scheduled for a detailed workup. About 2 months later, while at rest, he suddenly developed extreme difficulty breathing and was rushed to the emergency department where a tracheostomy was performed due to upper airway obstruction. There was no definite …

MRI and clinical studies of facial and bulbar muscle involvement in MuSk antibody-associated myasthenia gravis

MRI and clinical studies of facial and bulbar muscle involvement in MuSk antibody-associated myasthenia gravis

MRI and clinical studies of facial and bulbar muscle involvement in MuSK antibody-associated myasthenia gravis

A proportion of patients with myasthenia gravis (MG) without acetylcholine receptor (AChR) antibodies have antibodies to muscle-specific kinase (MuSK). MG with MuSK antibodies (MuSK-MG) is often associated with persistent bulbar involvement, including marked facial weakness and tongue muscle wasting. The extent of muscle wasting in MuSK-MG, and whether it is also found in the few acetylcholine receptor (AChR-MG) patients who have persistent bulbar involvement, is not clear. We studied 12 MuSK-MG patients and recruited 14 AChR-MG patients matched broadly for age, sex ratio, duration of disease and degree of ocular, bulbar and facial weakness. We used coronal and sagittal T1-weighted (T1W) and T2-weighted (T2W) magnetic resonance imaging (MRI) to assess muscle wasting in facial and tongue muscles. Hyperintense signal on T1W MRI and comparison of axial T1W sequences with cUTE sequences were used to assess fibrous/fatty tissue in the tongue. We compared the results with those of four patients with myotonic dystrophy and 12 healthy individuals. We correlated the changes with clinical and treatment histories, and established a new ocular-bulbar-facial-respiratory (OBFR) score. At the time of study, none of the clinical measures, including the OBFR score, differed between the two MG groups. MRI demonstrated thinning of the buccinator, orbicularis oris (O.oris) and orbicularis oculi (O.oculi) muscles in MuSK-MG patients compared with healthy controls, whereas thinning of these muscles was not significant in AChR-MG. Tongue areas with T1W high signal were increased in MuSK-MG patients and the intensity of the signal on axial T1W sequences was greater in MuSK-MG than in controls. To look for possible correlations between imaging and clinical findings, we pooled results from all MG patients. The duration of treatment with prednisolone at >40 mg on alternate days (AD) correlated positively with the percentage of tongue area with high signal (P = 0.006) and negatively with MRI measurements of individual muscles and with the mean muscle dimensions (P = 0.001). The new OBFR score correlated positively with current Myasthenia Gravis Foundation of America grades and with the percentage of high signal (P = 0.004) and negatively with the mean muscle dimensions (P < 0.001). The results show that bulbar and facial muscle weakness and wasting are associated with significant muscle atrophy and fatty replacement in MuSK-MG, which was not found in the AChR-MG patients. MuSK antibodies per se may predispose to muscle thinning, but the difficulties in obtaining clinical remission under steroid therapy in some patients, resulting in long duration of treatment with higher doses (>40 mg AD), may be an additional factor.

Repetitive nerve stimulation of facial muscles in musk antibody–positive myasthenia gravis

To better define electrophysiological abnormalities in myasthenia gravis (MG) patients with muscle-specific tyrosine kinase (MuSK) antibodies (Ab), we compared electrophysiological features of 14 MuSK Ab-positive, 73 acetylcholine receptor antibody (AChR Ab)-positive, and 22 MuSK and AChR Ab-negative (seronegative) patients with generalized disease. Repetitive nerve stimulation (RNS) abnormalities were observed in 86% of MuSK Ab-positive and 82% of AChR Ab-positive patients but in only 55% of seronegative patients. RNS decrements in the orbicularis oculi were more common and severe in the MuSK Ab-positive patients than the other two groups. Single-fiber electromyography (SFEMG) of the extensor digitorum communis was abnormal in 90% of MuSK Ab-positive patients. The high frequency of RNS abnormalities in facial muscles in the MuSK Ab-positive population reflects the propensity for facial muscle involvement in this form of MG and emphasizes the importance of including facial muscles in RNS protocols when evaluating these patients.

The features of myasthenia gravis with autoantibodies to MuSK

Objectives: To determine if myasthenia gravis (MG) with antibodies to MuSK is a distinct subgroup of seronegative MG. Methods: We assayed antibodies to muscle specific tyrosine kinase (MuSK) in 55...

Facioscapulohumeral Muscular Dystrophy Type 1A in Northwestern Tuscany: A Molecular Genetics-based Epidemiological and Genotype–Phenotype Study

Facioscapulohumeral muscular dystrophy type 1A (FSHD1A) is an autosomal dominant inherited disorder characterized by early involvement of facial and scapular muscles with eventual spreading to pelvic and lower limb muscles. A high degree of clinical variability with respect to age at onset, severity, and pattern of muscle involvement, both between and within families, is present. For this reason, diagnosis of FSHD1A can be sometimes difficult and molecular diagnosis is then necessary. A clinical and molecular genetic-based epidemiological investigation has been carried out in the territory of northwestern Tuscany in central Italy to calculate the prevalence rate of FSHD1A as of March, 2004. The molecular diagnosis has been based on the detection of large deletions of variable size of kpnI repeat units on chromosome 4q35. Results have been compared to those of a previous study conducted in the same area in 1981 (in the premolecular diagnosis era). The minimum prevalence rate was 4.60 x 10(-5) inhabitants, a value four times higher compared to our previous study. No significant correlation between fragment size and clinical severity has been observed. This study confirms in an Italian population a prevalence rate of FSHD1A similar to that observed in other populations. Furthermore, it underlines the usefulness of routine adoption of the genetic testing in confirming clinical suspicion of FSHD1A as well as in correctly diagnosing atypical and otherwise misclassified cases.