People with nemaline myopathy (NM) usually experience delayed motor development, or no motor development in severe cases, and weakness may occur in all of the skeletal muscles, such as muscles in the arms, legs, torso, neck flexors, throat, and face.

The disorder is often clinically categorized into groups with wide ranges of overlapping severity, from the most severe neonatal form which is incompatible with life, to a form so mild that it may not be diagnosed since the person appears to function at the lowest end of normal strength and breathing adequacy.

NM shortens life expectancy, particularly in the more severe forms, but aggressive and proactive care allows most individuals to survive and even lead active lives.

Nemaline myopathy is one of the neuromuscular diseases covered by the Muscular Dystrophy Association in the United States.

Due to weakness in the trunk muscles, people with NM are prone to scoliosis, which usually develops in childhood and worsens during puberty.

[10] If the person with nemaline myopathy keeps an eye on his or her joints early on, the problems with them can be detected when they begin and their progression can be delayed.

Treatment of joint problems ranges from stretching exercises with physical therapy to surgical introduction of braces.

Infants with severe NM frequently experience respiratory distress at or soon after birth, although this is only found in the rarest forms.

Though respiratory compromise may not be immediately apparent in people with intermediate or mild NM, it often, but not always, exists to some extent.

As in many neuromuscular disorders, hypoventilation can begin insidiously, and it may cause serious health problems if not remedied by the use of noninvasive mechanical devices to assist breathing, particularly at night.

[citation needed] Bulbar (throat) muscle weakness is a main feature of nemaline myopathy.

People with NM often have hypernasal speech as a result of poor closure of the velopharyngeal port (between the soft palate and the back of the throat).

Children born with NM often gain strength as they grow, though the effect of muscle weakness on body features may become more evident with time.

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 nemaline rods, being observed at the microscopic level within muscle fibers.

[16] One reason why this is lower is because NM is associated with de novo mutations in ACTA1, occurring spontaneously in the egg or sperm.

[16] MYPN is the last found gene related to NM The risk of all cases of nemaline myopathy is the same in males and females.

At the electron microscopic level, rod-shaped components can often be seen in some of the muscle cells, and when seen, are diagnostic for the condition called nemaline rod myopathy.

[citation needed] Nemaline myopathy is usually genetic and shows traits in the affected individual from birth or an early age.

[11] A third kind of nemaline myopathy in the Skeletal Muscle α-Actin Gene ACTA1 is due to a recessive null mutation.

Nemaline myopathy is a very rare disease that only affects 1 out of 50,000 on average, although recent studies show that this number is even smaller.

Some people have seen mild improvements in secretion handling, energy level, and physical functioning with supplemental L-tyrosine, an amino acid that is available through health centers.

These two resources connect families and individuals interested in participating in research with the scientists that aim to treat or cure NM.

[27] However, Reye's results were never published because another doctor dismissed his finding of rods in the muscle tissue as an artifact of the biopsy.

[22] Laboratories performing research on NM are located around the world, notably in the United States, Canada, England, Finland, and Australia.

In March 2006, Niki Shisler released a book, Fragile, in which she recounted her experiences surrounding the birth of twin sons with severe NM.