Hypomyelination and congenital cataract

Also known as: HCC


Genetics Home Reference

Hypomyelination and congenital cataract is an inherited condition that affects the nervous system and the eyes. This disease is one of a group of genetic disorders called leukoencephalopathies. Leukoencephalopathies involve abnormalities of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve fibers and promotes the rapid transmission of nerve impulses. Hypomyelination and congenital cataract is caused by a reduced ability to form myelin (hypomyelination). Additionally, people with this disorder are typically born with a clouding of the lens (cataract) in both eyes.

People with this condition usually have normal development throughout the first year of life. Development slows around the age of 1. Most affected children learn to walk between the ages of 1 and 2, although they usually need some type of support. Over time they experience muscle weakness and wasting (atrophy) in their legs, and many affected people eventually require wheelchair assistance. Weakness in the muscles of the trunk and a progressive abnormal curvature of the spine (scoliosis) further impair walking in some individuals. Most people with hypomyelination and congenital cataract have reduced sensation in their arms and legs (peripheral neuropathy). In addition, affected individuals typically have speech difficulties (dysarthria) and mild to moderate intellectual disability.

Go To Source: Genetics Home Reference


Hypomyelination-congenital cataract is characterized by the onset of cataract either at birth or in the first two months of life, delayed psychomotor development by the end of the first year of life and moderate intellectual deficit.

Go To Source: Orphanet


Medical Term Other Names Description
Scoliosis Curved spine, Abnormal curving of the spine, Curvature of spine [more] The presence of an abnormal lateral curvature of the spine.
Peripheral neuropathy Neuropathy, Peripheral neuritis, Peripheral nerve damage [more] Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.
Dysarthria Difficulty articulating speech, Dysarthric speech Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.
Congenital cataract Congenital cataracts, bilateral, Cataracts, lenticular, bilateral, Bilateral cataracts [more] A congenital cataract.
Muscle weakness Muscular weakness Reduced strength of muscles.
Abnormality of brain morphology Abnormal shape of brain, Abnormality of the brain A structural abnormality of the brain, which has as its parts the forebrain, midbrain, and hindbrain.
Impulsivity Impulsive Acting on the spur of the moment in response to immediate stimuli; acting on a momentary basis without a plan or consideration of outcomes; difficulty establishing or following plans; a sense of urgency and self-harming behavior under emotional distress.
CNS hypomyelination hypomyelination Reduced amount of myelin in the central nervous system resulting from defective myelinogenesis.
Delayed speech and language development Poor speech acquisition, Deficiency of speech development, Impaired speech development, Speech and language difficulties, Language delayed, Language development deficit, Impaired speech and language development, Delayed speech development, Speech delay, Language delay, Speech difficulties, Delayed speech, Delayed speech acquisition, Late-onset speech development, Speech and language delay, Delayed language development [more] A degree of language development that is significantly below the norm for a child of a specified age.
Leukoencephalopathy This term describes abnormality of the white matter of the cerebrum resulting from damage to the myelin sheaths of nerve cells.
Cataract Lens opacities, Lens opacity, Cloudy lens [more] A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule.
Global developmental delay Psychomotor developmental delay, Psychomotor retardation, Developmental delay, Lack of psychomotor development, Cognitive delay, Delayed intellectual development, Delayed milestones, Psychomotor development deficiency, Developmental retardation, Motor and developmental delay, Developmental delay in early childhood, Retarded psychomotor development, Retarded mental development, Delayed cognitive development, Retarded development, Delayed developmental milestones, Delayed development, Psychomotor development failure, Mental and motor retardation, Psychomotor delay, Delayed psychomotor development [more] 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.

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