This hypotonia panel includes multiple assays: This test is indicated for newborns with isolated, congenital hypotonia.ĭMPK, SMN1, SMN2, SNRPN Test Description:.Approximately 2% of individuals have other imprinting center defects or rarely, a balanced chromosome rearrangement involving chromosome 15. Approximately 25%-35% of individuals have maternal uniparental disomy, receiving two copies of the maternal chromosome 15 and no paternal chromosome 15. Approximately 70% of individuals have a deletion in the paternal 15q11.2-q13 region. PWS is caused by absence of the paternally derived 15q11.2-q13 region by one of several genetic mechanisms. However, in the neonatal period, the disorder may manifest only as isolated hypotonia, usually accompanied by feeding problems, with no obvious dysmorphic features. Many individuals with PWS may have recognizable patterns of behavior marked by stubbornness, and temper tantrums. Children with PWS can have short stature, hypogonadism, small hands and feet, and mild to moderate intellectual disability. An insatiable appetite may develop in later infancy or early childhood and can lead to obesity if not controlled. Prader-Willi syndrome (PWS) is characterized by neonatal onset of severe hypotonia, feeding difficulty and failure to thrive, which may be preceded by decreased fetal movement in utero. This assay tests for the common SMN1 and SMN2 deletions. Establishing the copy number of SMN2 can help determine phenotype severity in SMA patients and eligibility for therapies. The presence of a functioning SMN2 gene results in a small amount of full-length functional transcripts. Approximately 2%-5% of patients are compound heterozygotes for an SMN1 deletion and an SMN1 intragenic mutation. Approximately 95%-98% of those affected will have loss of both copies of the SMN1 gene. Spinal muscular atrophy (SMA) is characterized by a loss of motor nerves in the spinal cord and brain stem, which leads to symmetrical, progressive muscle weakness and atrophy. The congenital form of DM1 is caused by a DMPK allele with >1000 CTG repeats. The size of the repeat expansion correlates with the severity of the phenotype. DM1 is an autosomal dominant disorder, associated with an expansion of an unstable trinucleotide (CTG) repeat in the DMPK gene. The congenital form typically presents with hypotonia, muscle weakness, or respiratory distress, and may progress to include intellectual disability and early death. Severity and age of onset vary widely, and the disease is broadly classified into 3 types: mild, classic, and congenital. Myotonic dystrophy, type I (DM1) is the most common type of muscular dystrophy in adults and affects the skeletal and smooth muscle. The Congenital hypotonia panel consists of tests for three genetic conditions most often associated with isolated congenital hypotonia in newborns: myotonic dystrophy (type 1), spinal muscular atrophy, and Prader-Willi syndrome. Please include clinical notes and pedigree.Pediatric Molecular Genetics Test Requisition Form.Peripheral blood: 2-3 mL EDTA whole blood (Neonates: 1 mL EDTA)Ĩ1331 x1, 81400 x1, 81404 x1 Ordering Requirements:.To discuss minimum acceptable specimens for neonatal patients or for sample types not listed, please contact Allele Diagnostics. Specimens should be shipped at room temperature in a leak-proof, rigid container with overnight delivery. ![]() Congenital hypotonia panel: DM1, SMA, PWS 1 Test #:
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