<unk>  is caused by mutations in one of at least 11 different genes.<unk>  is a clinically and genetically heterogeneous disorder and both autosomal dominant and autosomal recessive forms can occur. Diagnosis is made based upon clinical signs such as muscle weakness, absent or low deep tendon reflexes (hyporeflexia), and a high-arched palate, along with electron-dense aggregates, called<unk>  rods, being observed at the microscopic level within muscle fibers. Genetic confirmation through identification of a known genetic mutation in the patient is also an important component of diagnosis. The two most common gene mutations causing<unk>  are found on NEB or ACTA1. Mutations of the NEB gene usually result in symptoms present at birth or beginning in early childhood. This mutation results in about 50% of affected<unk>  patients. The most common inheritance pathway for those with mutations in NEB is autosomal recessive in which each parent carries one mutated copy along with one normal functioning copy of the gene, and they pass the mutated copy to their offspring. In some cases, occasionally with ACTA1 mutations,<unk>  can be caused by an inheritance pattern of autosomal dominance. This mutation results in about 15 to 25 percent of<unk>  cases. One reason why this is lower is because<unk>  is associated with de novo mutations in ACTA1, occurring spontaneously in the egg or sperm. When the condition is heritable, each pregnancy with the same partners has the same risk of passing the mutated genes to offspring. New mutations (de novo) can also occur causing<unk>  and de novo mutations have been most often found to occur in the ACTA1 gene. MYPN is the last found gene related to<unk>  The risk of all cases of<unk>  is the same in males and females. An example of muscle cells with rods. The rods have been stained red and are located on the inside of the plasma membrane. +Summary of Molecular Genetic Testing Used in<unk>  Gene 1 Proportion of<unk>  Attributed to Mutation of This Gene Test Method NEB Up to 50% Sequence analysis Deletion/duplication analysis & targeted analysis for pathogenic variants ACTA1 15%-25% Sequence analysis Deletion/duplication analysis TPM3 2%-3% Sequence analysis Deletion/duplication analysis TPM2 <1% Sequence analysis Deletion/duplication analysis TNNT1 Almost exclusively in Old Amish Sequence analysis Deletion/duplication analysis CFL2 Rare Sequence analysis KBTBD13 Unknown Sequence analysis KLHL40 20% Sequence analysis KLHL41 Unknown Sequence analysis LMOD3 Unknown Sequence analysis Unknown NA NA The physical capabilities of a given person with<unk>  do not correlate well either with genotype or with muscle pathology as observed in the biopsy.
Nemaline myopathy
Brody myopathy
Centronuclear myopathy
Bethlem myopathy
Muscular dystrophy
Metabolic myopathy
Inflammatory myopathy
Hereditary inclusion body myopathy