An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age.

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.

Encephalopathy is a term that means brain disease, damage, or malfunction. In general, encephalopathy is manifested by an altered mental state.

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

A disorder of muscle unrelated to impairment of innervation or neuromuscular junction.

Generalized muscular hypotonia (abnormally low muscle tone).

Nemaline rods are abnormal bodies that can occur in skeletal muscle fibers. The rods can be observed on histological analysis of muscle biopsy tissue or upon electron microscopy, where they appear either as extensions of sarcomeric Z-lines, in random array without obvious attachment to Z-lines (often in areas devoid of sarcomeres) or in large clusters localized at the sarcolemma or intermyofibrillar spaces.

An abnormal buildup of lactic acid in the body, leading to acidification of the blood and other bodily fluids.

The birth of a baby of less than 37 weeks of gestational age.