Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two congenital anterior horn cell diseases may be responsible for neonatal muscular atrophy. The acute Werdnig-Hoffmann disease (SMA-I) has a progressive course, the anterior horn cell degeneration (AHCD) is non progressive in the postnatal period. In case of Werdnig-Hoffmann disease symptoms of hypotonia and muscle weakness may be present at birth, but become progressive during the first months of live. The full clinical picture of AHCD is present at birth. In the latter clinical symptoms of fetal hypokinesia may be noticed during intrauterine life. Histopathological muscle investigation reveals a more or less characteristic neurogenic pattern in Werdnig-Hoffmann disease, in AHCD neurogenic and myopathic changes are variable. Two examples of these diseases will be discussed.
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PMID:[Spinal muscular atrophy in young infants]. 279 98

Two affected siblings with infantile spinal muscular atrophy (SMA I) presented with generalized muscular hypotonia, which progressed to early death. Quadriceps muscle biopsy did not show the typical neurogenic pattern of spinal muscular atrophy. The histochemical fiber type determination revealed a predominance of type II fibers without type I hypertrophy, an unprecedented finding in spinal muscular atrophy. Sural nerve biopsy exhibited findings typical for axonal neuropathy. In one patient, electrical stimulation of peripheral nerves showed an inexcitability of motor and sensory nerves. Genetic studies revealed homozygous deletions of the telomeric survival motor neuron (SMN) gene and the neuronal apoptosis inhibitory protein (NAIP) gene in the affected children. This is the second case report of molecular genetically proven spinal muscular atrophy associated with axonal neuropathy. We conclude atypical findings on muscle biopsy and evidence of axonal neuropathy are compatible with the diagnosis of infantile spinal muscular atrophy.
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PMID:Axonal neuropathy and predominance of type II myofibers in infantile spinal muscular atrophy. 970 81

Spinal muscular atrophy (SMA) or Werdnig-Hoffmann disease is the second most common neuromuscular disease, with 25% of cases presenting in infancy. Deletions in the survival motor neuron gene are believed responsible for autosomal-recessive SMA. SMA affects about 1 in 10,000 births. Symptomatic newborns have severe hypotonia, may have respiratory distress, may be unable to feed, and rapidly progress to death early in infancy. This paper describes another early pulmonary manifestation of SMA, i.e., migrating or rotating atelectasis, in 2 patients with infantile SMA. Migrating or rotating atelectasis may suggest the diagnosis of SMA.
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PMID:Migrating atelectasis in Werdnig-Hoffmann disease: pulmonary manifestations in two cases of spinal muscular atrophy type 1. 1042 16

The classical form of severe spinal muscular atrophy (SMA type 1; Werdnig-Hoffmann disease) has a very consistent clinical phenotype that is well recognized by paediatricians. It usually presents at birth or within the first few months of life. There is general hypotonia, with axial and limb weakness; the legs are affected more than the arms and proximal muscles more than distal, leaving residual spontaneous activity in the feet and in the forearms and hands. Facial muscles are spared so that the infant usually has a bright normal expression. The intercostal muscles are always affected, whereas the diaphragm is spared, allowing adequate spontaneous respiratory activity until the infants are precipitated into respiratory failure by an incidental respiratory infection, or aspiration. With rare exception they die by 2 years of age with a median around 7 months and with about 80% of the children dying by the time they are 1 year old. There is a consistent homozygous deletion in exons 7 and 8 of the telomeric copy of the survival motor neuron (SMN) gene. In the current issue of the journal, MacLeod and her colleagues have documented five cases of more severe spinal muscular atrophy, with a history of diminished fetal movements in utero and presenting at birth with asphyxia and severe weakness.
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PMID:Very severe spinal muscular atrophy (SMA type 0): an expanding clinical phenotype. 1070 May 41

We report the association of pontocerebellar hypoplasia and anterior horn cell disease in three female siblings. One child presented with the classical clinical and neuropathological features of pontocerebellar hypoplasia with associated anterior horn cell disease, described by Barth as pontocerebellar hypoplasia type I. This patient showed polyhydramnios, congenital contractures, respiratory insufficiency, hypotonia, areflexia, listlessness and myoclonic seizures. Postmortem examination revealed a loss of neurons and reactive gliosis in the pontocerebellum and in addition anterior horn cell atrophy resembling Werdnig-Hoffmann disease. Another sibling demonstrated the same clinical symptoms. However neuropathological findings showed evidence for pontocerebellar hypoplasia only. The third sibling was examined after induced fetal abortion because of prenatally diagnosed arthrogryposis. Anterior horn cell disease was obvious histologically whereas pontocerebellar hypoplasia could not be demonstrated due to cerebral autolysis. The similar clinical and neuropathological findings in the three reported siblings suggest a common genetic defect with different patterns of pontocerebellar hypoplasia and associated anterior horn cell disease. The gene defect of this rare disorder is still unknown. The 'survival motor neuron' gene of spinal muscular atrophy was not found in these three siblings.
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PMID:Familial pontocerebellar hypoplasia type I with anterior horn cell disease. 1072 90

We report the case of a 3-(1/2)-year-old girl with hypotonia, multiple joint contractures, hip luxation, arachnodactyly, adducted thumbs, dolichostenomelia, and abnormal external ears suggesting the diagnosis of congenital contractural arachnodactyly (CCA). The serum muscle enzymes were normal and the needle electromyography showed active and chronic denervation. The muscle biopsy demonstrated active and chronic denervation compatible with spinal muscular atrophy. Analysis of exons 7 and 8 of survival motor neuron gene through polymerase chain reaction did not show deletions. Neurogenic muscular atrophy is a new abnormality associated with CCA, suggesting that CCA is clinically heterogeneous.
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PMID:Congenital contractural arachnodactyly with neurogenic muscular atrophy: case report. 1140 38

Causes of hypotonia in the newborn can be broadly categorized into two classifications. Hypotonia with a supraspinal origin may be seen with systemic disease, hypoxic ischemic encephalopathy, cerebral malformations, syndromes (for example: Down, Prader-Willi, Lowe, Zellweger, Smith-Lemli-Opitz), and c-spine injury. Disorders of the motor unit that present with hypotonia in the newborn period include SMA, congenital myotonic dystrophy, congenital myasthenia gravis, and congenital myopathies. Central core disease is one of the classic congenital myopathies that can be differentiated based on characteristic histologic findings. Muscle fiber samples from patients with central core disease possess distinct morphology that can be diagnostic. Many infants may not exhibit muscle weakness in the newborn period, although there have been rare cases of profound hypotonia and respiratory failure. Clearly, muscle biopsy is the gold standard and is indicated for any infant with marked hypotonia that is not thought to be supraspinal in origin.
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PMID:The hypotonic infant: case study of central core disease. 1259 91

We describe 6 unrelated patients affected by infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1) with prolonged survival upon mechanical ventilation (4.5-11 years), which has not been reported before. Biallelic mutations in the IGHMBP2 gene proved the diagnosis of SMARD1 in all patients. Disease onset was in the first 2 months in the described patients, starting with generalised hypotonia, failure to thrive, and early breathing difficulties. Diaphragmatic palsy was diagnosed and permanent ventilation was initiated 2-8 months after onset. Within months a more distal muscular atrophy became evident associated with joint contractures (talipes), hand drops, and fatty finger pads. Motor development remained minimal, loss of function was observed within the first year after which no further progression was recorded. Voiding dysfunction with reflux nephropathy was observed in 3 patients and has not been reported before. Further evidence of autonomic nerve dysfunction resulting in cardiac arrhythmia, hypertension, and excessive sweating was given in 2 patients. Investigative results were largely compatible with those obtained in classic SMA. However, neurogenic atrophy muscle was more pronounced in distal muscles, if examined, and there was evidence of peripheral nerve involvement at least in some patients.
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PMID:Long-term observations of patients with infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1). 1524

Spinal Muscular Atrophy (SMA) is an autosomal recessive disease characterized by diffuse proximal and distal weakness due to deletions of the survival motor neuron (SMN) gene localised on chromosome 5q13. Pathological studies show decreased numbers of motorneurons in spinal cord. SMA was initially sub-classified clinically into three types base on age at onset and clinical course. SMA type 1, Werdnig-Hoffmann disease, has an onset within the first 6 months and death within the first two years. In contrast, SMA type II has an onset after six months of life and the children achieve the ability to sit unaided. Children with SMA type III (Kugelberg-Welander) usually have normal milestones in the first year and achieve the ability to walk but then show evidence of mild weakness. The prognosis is good and the clinical course is not (or very slowly) progressive. Recently, Dubowitz described a new form of SMA called type 0 with a neonatal onset, facial weakness, progressive and fatal clinical course. These infants show generalised hypotonia, the lower limbs are more affected than the upper with marked weakness of all axial muscles. We report a case of SMA, uncommon for the early onset and the respiratory difficulties. The diagnosis has been done by genetic analyses showing a SMN mutation.
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PMID:[Neonatal muscular spinal atrophy: a case report]. 1570 Jul 40

A 2-year 9-month-old male was referred for gait disturbances. Main complaints were abnormal gait with frequent falls observed as soon as he began to walk unaided, at 18 months of age. The first neurologic examination revealed symmetric and proximal weakness in the lower limbs with difficulty running and walking upstairs. Deep tendon reflexes were decreased, and generalized hypotonia was observed. Three months later, at 3 years of age, he had lost independent gait, and 1 month later he could not stand unaided. DNA analysis revealed homozygous deletion in exons 7 and 8 of SMN1 gene, confirming the diagnosis of spinal muscular atrophy. According to the current classification, this patient would be classified as spinal muscular atrophy type III. The distinctive feature of this case was the short time elapsed (18 months) between onset of spinal muscular atrophy and the age at which he lost ambulation. This patient reinforces the notion that late onset of symptoms in spinal muscular atrophy and acquisition of independent gait do not exclude a rapidly progressive motor deterioration, which is important when talking with families about outcome. In those rapidly progressive cases, when promptly available, testing for SMN1 gene will prevent unnecessary, invasive, or uncomfortable procedures such as lumbar puncture, electromyography, or spinal cord magnetic resonance imaging.
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PMID:Rapidly progressive spinal muscular atrophy in an ambulatory 2-year-old male. 1599 24


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