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Genetics
Published in Ibrahim Natalwala, Ammar Natalwala, E Glucksman, MCQs in Neurology and Neurosurgery for Medical Students, 2022
Ibrahim Natalwala, Ammar Natalwala, E Glucksman
Werdnig-Hoffmann disease (answer C) is also known as spinal muscular atrophy type 1 (SMA1). It is an autosomal recessive condition that leads to degeneration of anterior horn cells resulting in muscle weakness and wasting. It characteristically affects those aged less than 6 months and hence it can present as ‘floppy baby’.
Neuromuscular disorders
Published in Angus Clarke, Alex Murray, Julian Sampson, Harper's Practical Genetic Counselling, 2019
In the most common type, type I, known as severe infantile spinal muscular atrophy (Werdnig-Hoffmann disease), onset is at or shortly after birth, with death – in the absence of treatment – invariably before 2 years and usually before 18 months. Severity in other affected sibs is closely correlated, so that the chance of a subsequent affected infant surviving in the long term is very small, as is the chance of an infant who is clinically normal at 6 months going on to develop the disease. This can be confirmed by molecular analysis. DNA analysis or banking on the first affected child is vital to allow subsequent prenatal diagnosis. There have been some promising results in trials of gene therapy for this disease.
Economic burden of spinal muscular atrophy in the United States: a contemporary assessment
Published in Journal of Medical Economics, 2020
Marcus Droege, Douglas Sproule, Ramesh Arjunji, Marjolaine Gauthier-Loiselle, Martin Cloutier, Omar Dabbous
Spinal muscular atrophy (SMA) is a severe neuromuscular disease characterized by the degeneration of alpha motor neurons in the spinal cord, resulting in progressive proximal muscle weakness and paralysis1,2. It is the leading genetic cause of infant mortality, affecting ∼1/10,000–1/11,000 live births1,2. The disease is caused by mutations in the survival motor neuron 1 gene (SMN1), which leads to loss of motor neurons with resulting muscular atrophy and subsequent impairment of motor neuron function2,3. SMA is clinically classified into five phenotypes (SMA types 0–4) according to the age at disease onset and motor function achieved1,2. SMA type 0 is the most severe and is typically fatal in utero or shortly after birth. SMA type 1 (SMA1; also named Werdnig-Hoffmann disease) is the most common type, accounting for ∼50–60% of all SMA cases2,4. Infants with SMA1 usually have onset of clinical signs within the first 6 months of life, and fail to reach basic developmental motor milestones, such as the ability to sit without assistance4,5. In the absence of external intervention, patients with SMA1 generally do not survive beyond the first 2 years1,6. SMA types 2, 3, and 4 are associated with progressively later disease onsets and are generally less severe and more stable in disease course, with minimal to no change in life expectancy1,2.
The split hand in amyotrophic lateral sclerosis: a possible role for the neuromuscular junction
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2019
Mamede de Carvalho, Michael Swash
The “split hand” phenomenon in amyotrophic lateral sclerosis (ALS), first described by Wilbourn and Sweeney (1), consists of pronounced atrophy of the thenar muscles, with relative sparing of the hypothenar muscles. Although recognized as typical of ALS, Wilbourn (2) and others (3) found that this phenomenon rarely occurs in other neuromuscular disorders, e.g. Werdnig Hoffmann disease, distal spinal muscular atrophy, Hirayama disease, remote polio, Machado–Joseph disease, and in aging (4). Although the split hand phenomenon is considered a feature usually associated with ALS (2) it has been reported absent in about 50% of patients with ALS, a finding that itself requires explanation (5).
Spinal muscular atrophy – a revisit of the diagnosis and treatment modalities
Published in International Journal of Neuroscience, 2019
Gaurava Srivastava, Preeti Srivastava
Type I [(MIM 253300) (Werdnig-Hoffmann disease)] (Severe) is the most severe form, having onset in utero, reduced fetal movements in the first six months of life, hypotonia, progressive muscle wasting, fasciculation, paucity of movement and areflexia. Affected children have normal intelligence but are unable to sit unaided, have feeding difficulties, and die from respiratory failure or aspiration before the age of 2 years [21].