Nemaline myopathy (NM) is a neuromuscular disorder characterized by muscle weakness and the presence of rod-shaped structures (nemaline bodies or rods) in affected muscle fibers. The typical, and most common, form of NM is characterized by the infantile onset of a slowly progressive or non-progressive weakness of facial, bulbar, and respiratory muscles and neck flexors. Initial weakness is primarily proximal, with later distal involvement. The typical form of NM has an autosomal recessive pattern of inheritance, and results from mutations in the NEB gene. The overall incidence of NM is estimated to be is 2 in 100,000 live births; however a founder mutation in NEB (p.R2478_D2512del) has been identified in the Ashkenazi Jewish population. The carrier frequency for this mutation in this population is estimated to be 1 in 168. Testing for this mutation is expected to detect at least 95% of Ashkenazi Jewish carriers of NM. Carrier screening for NM may be considered for individuals of Eastern European (Ashkenazi) Jewish ancestry before or during pregnancy.
Full gene sequencing is available for reproductive partners of known mutation carriers. Prenatal diagnosis is also available. Prior to ordering prenatal testing, please contact our laboratory at 212-241-7518 to discuss.
1. Anderson SL. et al., (2004) Nemaline myopathy in the Ashkenazi Jewish population is caused by a deletion in the nebulin gene. Hum Genet. Aug;115(3):185-90.
2. Pelin K. et al., (1999) Mutations in the nebulin gene associated with autosomal recessive nemaline myopathy. Proc Natl Acad Sci U S A. Mar 2;96(5):2305-10.
3. Sanoudou D, Beggs AH (2001) Clinical and genetic heterogeneity in nemaline myopathy—a disease of skeletal muscle thin filaments. Trends Mol Med 7:362–368.
4. Wallgren-Pettersson C (1990) Congenital nemaline myopathy: a longitudinal study. Commentationes Physico-Mathematicae 111:1–102.
5. Scott, S.A., Edelmann, L., Liu, L., Luo, M., Desnick, R.J. and Kornreich, R. Experience with carrier screening and prenatal diagnosis for sixteen Ashkenazi Jewish Genetic Diseases. Hum. Mutat. 31:1-11, 2010.
Post-natal: Two 5-10 mL tubes of anticoagulated blood in EDTA (lavender top) or two 5-10 mL tubes of anticoagulated blood in ACD (yellow top).
- Chorionic Villi: 5-10 mg in conical tube with sterile saline OR transport media
- Amniotic Fluid: 10 ml in conical tube
- Cultured Cells: two confluent T-25 flasks
Additionally, please send:
- 5-10 ml maternal blood in EDTA (lavender top) required to perform MCC studies on all prenatal samples and in case maternal confirmation studies are necessary
- 5-10 ml paternal blood in EDTA (lavender top) in case paternal confirmation studies are necessary
Shipping: Ship at room temperature.
Turnaround Time: 10-14 days
CPT Code: 81401
Consent and Requisition Forms: Carrier Screening Requisition and Consent [PDF]
Additional Information: Expanded Ashkenazi Jewish Carrier Screening brochure [PDF]
Related Tests: Ashkenazi Jewish Carrier Test Panel