Novel mutations expand the clinical spectrum of DYNC1H1-associated spinal muscular atrophy

OBJECTIVE To expand the clinical phenotype of autosomal dominant congenital spinal muscular atrophy with lower extremity predominance (SMA-LED) due to mutations in the dynein, cytoplasmic 1, heavy chain 1 (DYNC1H1) gene. METHODS Patients with a phenotype suggestive of a motor, non-length-dependent neuronopathy predominantly affecting the lower limbs were identified at participating neuromuscular centers and referred for targeted sequencing of DYNC1H1. RESULTS We report a cohort of 30 cases of SMA-LED from 16 families, carrying mutations in the tail and motor domains of DYNC1H1, including 10 novel mutations. These patients are characterized by congenital or childhood-onset lower limb wasting and weakness frequently associated with cognitive impairment. The clinical severity is variable, ranging from generalized arthrogryposis and inability to ambulate to exclusive and mild lower limb weakness. In many individuals with cognitive impairment (9/30 had cognitive impairment) who underwent brain MRI, there was an underlying structural malformation resulting in polymicrogyric appearance. The lower limb muscle MRI shows a distinctive pattern suggestive of denervation characterized by sparing and relative hypertrophy of the adductor longus and semitendinosus muscles at the thigh level, and diffuse involvement with relative sparing of the anterior-medial muscles at the calf level. Proximal muscle histopathology did not always show classic neurogenic features. CONCLUSION Our report expands the clinical spectrum of DYNC1H1-related SMA-LED to include generalized arthrogryposis. In addition, we report that the neurogenic peripheral pathology and the CNS neuronal migration defects are often associated, reinforcing the importance of DYNC1H1 in both central and peripheral neuronal functions

Neurofibromatosis type 1: een overzicht van 196 patiënten

OBJECTIVE: To analyse symptoms and complications in patients with neurofibromatosis type 1 (NF1). All patients were examined in a multidisciplinary outpatient neurofibromatosis clinic during a period of 10 years. DESIGN: Retrospective. SETTING: Academic Medical Center, University Hospital Amsterdam, the Netherlands. METHOD: All data on 450 persons visiting the neurofibromatosis clinic were stored in a database. Data were collected on the results of dermatological, neurological, ophthalmological and general examinations and on family history. For this study the follow-up data of 196 patients with a definite diagnosis of 'NF1' were analysed. RESULTS: In childhood diagnosis NF1 is predominantly based on specific dermatological symptoms such as > 6 café-au-lait (CAL) spots and freckling and on the presence of characteristic ophthalmological signs as two or more Lisch nodules. In this study the frequencies of these symptoms were 98% (CAL). 92% (freckles), and 93% (Lisch nodules) respectively. The frequencies of well-known complications of this disorder are comparable with the literature findings. In this study we found optic pathway glioma (OPG) in 10%, macrocephaly in 36%, hydrocephalus in 5%, retardation in 14%, brain tumours in 5%, kyphoscoliosis in 13%. renal artery stenosis in 0.5% and neurofibrosarcoma in 0.5% of NF1 patients. In children the degree of severity of this disorder is less than in adults, demonstrating the progressive character of the disease. CONCLUSION: The diagnosis of 'NF1' can usually be made by dermatological and ophthalmological examination. In case of a definite diagnosis in childhood regular follow-up is recommended since severe complications, such as OPG and kyphoscoliosis, may occur specifically in childhood and adolescence. For adult patients determination of the degree of severity is essential for the decision whether or not they need regular follow-up; they should have their blood pressure measured annuall

GLUT-1 deficiency without epilepsy--an exceptional case

The GLUT-1 deficiency is a metabolic disorder caused by a defect in glucose transport across the blood-brain barrier as a result of a defect in the glucose-transport protein. Patients present with epileptic seizures, delayed development, ataxia and hypotonia, and in many cases acquired microcephaly. In most patients, treatment with a ketogenic diet proved to be successful in controlling the epilepsy. We report a 9-year-old boy with retardation and ataxia, but without epilepsy, caused by GLUT-1 deficiency, proven biochemically and by DNA analysis. Treatment with a medium-chain triglyceride ketogenic diet had a beneficial effec

Molybdenum-cofactor deficiency: an easily missed cause of neonatal convulsions

Intractable seizures in the neonatal period may be caused by molybdenum-cofactor deficiency, an inborn error which combines the deficiencies of sulphite oxidase and xanthine dehydrogenase. The neurological symptoms of molybdenum cofactor and isolated sulphite oxidase deficiencies are identical. Two new cases are reported, and the literature on neonatal convulsions due to molybdenum-cofactor and sulphite deficiencies is reviewed. Because of the high incidence of neonatal convulsions a search for this deficiency is advocated in each case of unexplained refractory neonatal convulsions. Diagnosis may be missed or delayed on standard metabolic screening for several reasons discussed. By simply using a sulphite strip test in a fresh urine sample an indication for the defect can be obtained. Antenatal diagnosis can be performed by assay of sulphite oxidase activity in a chorionic villus sampl