Journal of Neuromuscular Diseases 2 (2015) 229–240 229 DOI 10.3233/JND-150093 IOS Press Research Report Laminin ␣2 Deficiency-Related Muscular Dystrophy Mimicking Emery-Dreifuss and Collagen VI related Diseases Isabelle Nelsona,b, Tanya Stojkovica,b,c,Valerie´ Allamanda,b, France Leturcqa,d, Henri-Marc Becane´ b,c, Dominique Babutye, Annick Toutainf , Christophe Beroud´ g, Pascale Richardh, Norma B. Romeroa,b,c,i, Bruno Eymardb,c, Rabah Ben Yaoua,b,c and Gisele` Bonnea,b,∗ aSorbonne Universite´s, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center of Research in Myology, F-75013 Paris, France bInstitut de Myologie, F-75013, Paris, France cAP-HP, Groupe Hospitalier La Pitie´-Salpˆetri`ere, Centre de re´fe´rence des maladies neuromusculaires Paris Est, F-75013, Paris, France dAP-HP, Groupe Hospitalier Cochin-Broca-Hˆotel Dieu, Laboratoire de biochimie et ge´ne´tique mole´culaire, Paris, France eService de Cardiologie, Hˆopital Trousseau, CHU Tours, Tours, France f Service de Ge´ne´tique, Hˆopital Bretonneau, CHU Tours, Tours, France gINSERM UMR S910, AP-HM, service de ge´ne´tique me´dicale, Aix Marseille Universite´, Marseille, France hAP-HP, Groupe Hospitalier La Pitie´-Salpˆotri`ere, U.F. Cardioge´ne´tique et Myoge´ne´tique, Service de Biochimie Me´tabolique, F-75013, Paris, France iUnite´de morphologieneuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitie´-Salpˆetri`ere, F-75013, Paris, France Abstract. Background: Laminin ␣2 deficient congenital muscular dystrophy, caused by mutations in the LAMA2 gene, is characterized by early muscle weakness associated with abnormal white matter signal on cerebral MRI. Objective: To report on 4 patients with LAMA2 gene mutations whose original clinical features complicated the diagnosis strategy. Methods: Clinical, electrophysiological, muscle imaging and histopathological data were retrospectively collected from all patients. DNA samples were analysed by next-generation sequencing or direct gene sequencing. Laminin ␣2 was analysed by western-blot and immunohistochemistry. Results: The four patients achieved independent walking. All had proximal muscle weakness with scapular winging and prominent joint contractures without peripheral neuropathy. During follow-up, two patients suffered from refractory epilepsy associated with brain leukoencephalopathy in one, polymicrogyria and lissencephaly without white matter changes in the other. In two patients, the distribution of fatty infiltration resembles that of collagen-VI related myopathies. Dilated cardiomyopathy ∗Correspondence to: Gisele` Bonne, Sorbonne Universites,´ Babinski, 47 Boulevard de l’hopital,ˆ 75651 Paris cedex 13, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, France. Tel.: +33 142165723; Fax: +33 142165700; E-mail: Center for Research in Myology, Institut de Myologie, Batimentˆ [email protected]. ISSN 2214-3599/15/$35.00 © 2015 – IOS Press and the authors. All rights reserved This article is published online with Open Access and distributed under the terms of the Creative Commons Attribution Non-Commercial License. 230 I. Nelson et al. / Expanding LAMA2 Mutation-Associated Clinical Spectrum with conduction defects, suggestive of Emery-Dreifuss myopathy, emerged in two of them within the 4th decade. Molecular diagnosis remained elusive for many years. Finally, targeted capture-DNA sequencing unveiled the involvement of the LAMA2 gene in two families, and led us to further identify LAMA2 mutations in the remaining family using Sanger sequencing. Conclusions: This report extends the clinical and radiological features of partial Laminin ␣2 deficiency since patients showed atypical manifestations including dilated cardiomyopathy with conduction defects in 2, epilepsy in 2, one of whom also had sole cortical brain abnormalities. Importantly, clinical findings and muscle imaging initially pointed to collagen-VI related disorders and Emery-Dreifuss muscular dystrophy. Keywords: Laminin alpha 2, LAMA2, congenital muscular dystrophy, Emery-Dreifuss muscular dystrophy, collagen VI-related myopathy, dilated cardiomyopathy INTRODUCTION MATERIAL AND METHODS Congenital muscular dystrophy (CMD) is a Clinical assessment clinically and genetically heterogeneous group of neu- romuscular disorders [1]. Laminin alpha 2-deficient Four patients including two isolated cases (Patients CMD (MDC1A, OMIM #607855) is characterized #1 and #2) and two brothers (Patients #3 and #4) by hypotonia at birth or within the first few months were included in this study (Fig. 1). Neurological of life, contractures of large joints, elevated serum assessment, CK levels, muscle imaging including creatine kinase (CK) levels and abnormal white mat- whole-body muscle MRI for patients #1 and #2 and ter changes although cognitive abilities are normal muscle CT-scan for patients #3 and #4, cardiac inves- [2–4]. MDC1A, caused by a deficiency in the ␣2 chain tigations including at least electrocardiogram (ECG) of laminin-211 [5] previously named merosin [6], is and echocardiography, pulmonary function tests, elec- the most represented form of CMD [7]. Typically, troneuromyography and brain MRI or CT scan were independent ambulation is not achieved in MDC1A retrospectively collected from medical files for each with complete laminin-alpha 2 deficiency. Only a few patient (Table 1). All biological samples (blood, skin reports have mentioned cardiac involvement associ- and muscle biopsies) were obtained after informed ated with MDC1A (for reviews see [8, 9]). Atypical consent from patients and their relatives. presentations such as adult onset limb-girdle muscular dystrophies with white matter abnormalities have been reported with partial laminin-alpha 2 deficiency [10, Histopathology, immunohistochemistry 11]. Numerous mutations of the LAMA2 gene encod- ing the ␣2 chain of laminin-211 have been identified, Muscle biopsy was performed in 3 out of the 4 scattered along the 64 coding exons and leading to patients. Biopsy specimens of deltoid muscle were partial or complete protein deficiency [4]. analysed by light microscopy [12]. Immunohisto- Here we report four adult patients in whom the initial chemical studies were carried out for all patients diagnosis suggested by clinical presentation and mus- on 10 ␮m cryosections for dystrophin, ␣-, ␤- and cle biopsy findings was mainly consistent with either γ-sarcoglycans, dysferlin, ␣-dystroglycan, desmin, Bethlem myopathy (BM) or Emery-Dreifuss mus- ␣B-crystallin, myotilin, myosin heavy chain, caveolin cular dystrophy (EDMD). Peculiar features included 3 and collagen VI. Laminin ␣2 chain immunostainings dilated cardiomyopathy (two patients) and epilepsy were performed after LAMA2 mutations identifica- (two patients) that occurred during follow-up. Ulti- tion and used 3 antibodies directed against the whole mately, molecular diagnosis was achieved through next protein (NCL-merosin, Leica Novocastra), the N- generation sequencing (NGS), revealing homozygous terminal 300 KDa fragment (4H8-2, Abcam) or the or compound heterozygous LAMA2 gene mutations. C-terminal 80KDa fragment (MAB 1922, Chemicon These findings extend the clinical spectrum of LAMA2 International). Representative images were obtained mutations to adults, clinically resembling Bethlem with an Axioplan 2 microscope (Zeiss) equipped with myopathy or Emery-Dreifuss muscular dystrophy and a HBO 100 mercury lamp (Zeiss) and captured using emphasize further the critical input of NGS in diag- Metaview software (Roper Scientific), using identical nosing atypical forms of myopathies. exposure time for each antibody. I. Nelson et al. / Expanding LAMA2 Mutation-Associated Clinical Spectrum 231 Fig. 1. Patients carrying LAMA2 mutations. Patient #1 presents distal and proximal joint contractures. The muscle CT scan showed a predomi- nantly central hypodensity in the rectus femoris (yellow arrows), in the peripheral region of the vastus lateralis (asterisks) and the gastrocnemius medialis and lateralis muscles (red arrows). Patient #2 also presents distal and proximal joint contractures. Whole body MR showed diffuse fatty infiltration of pelvic. The superficial layers of the vastus lateralis, semimembranosus, semitendinosus and gracilis muscles were less affected. The fatty infiltration surrounded the soleus muscle and was localized at the periphery of gastrocnemius medialis and lateralis, wheras the tibialis anterior, the extensors and the tibialis posterior muscle were almost spared. Brain MRI disclosed a posterior polymicrogyria (blue arrows) and lissencephaly (white arrows). Patient #3 and #4 have mild ankle and elbow contractures. Muscle CT scan showed marked hypodensity of the vastus lateralis and intermedius, the semimembranosus, the semitendinosus, the biceps femoris and the adductor muscles, paraspinal muscles, mild involvement of right peroneus longus muscle in patient #3 and peroneus longus and extensor digitorum longus muscles in patient #4, whereas the gracilis, sartorius, vastus medialis, rectus femoris, gastrocnemii, soleus, tibialis anterior muscles were spared. In the upper limbs, deltoid and biceps brachialis muscles present a mild fatty infiltration. Brain MRI of patient #3 showed a symmetric leukoencephalopathy (green arrows). Western blot analyses studies [13, 14]. After LAMA2 mutations identifica- tion, laminin ␣2 western blot was performed on muscle Western blot analyses were performed on proteins samples from patients #1, #2 and #3 as well as in 2 extracted from muscle biopsy for dystrophin, ␣-, ␤- control subjects and a previously identified