Hypotrichosis with juvenile macular dystrophy

A rare genetic disorder affecting hair and vision

Hypotrichosis with juvenile macular dystrophy (HJMD) is a rare genetic disorder characterized by sparse hair growth (hypotrichosis) and progressive vision loss due to macular dystrophy. This condition is inherited in an autosomal recessive pattern and is associated with mutations in the CDH3 gene.

Clinical Features

Hypotrichosis

Individuals with HJMD typically present with sparse scalp hair from birth. The hair is often thin, brittle, and may be slow-growing. Over time, affected individuals may experience further hair thinning, but complete baldness is uncommon.

Juvenile Macular Dystrophy

Fundus image of the left eye showing macular changes

The macular dystrophy associated with HJMD usually manifests in childhood or early adolescence. Patients experience progressive loss of central vision, which is crucial for tasks such as reading and recognizing faces. Peripheral vision is typically preserved. The condition is characterized by atrophy of the retina and changes in the retinal pigment epithelium.

Genetics

HJMD is caused by mutations in the CDH3 gene, which encodes the protein P-cadherin. This protein is involved in cell adhesion and is important for the normal development of hair follicles and retinal cells. The disorder follows an autosomal recessive inheritance pattern, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected.

Diagnosis

Diagnosis of HJMD is based on clinical examination, family history, and genetic testing. Ophthalmological assessments, including optical coherence tomography (OCT) and fundus photography, are used to evaluate the extent of macular degeneration.

OCT image showing retinal changes

Autofluorescence image of the retina

Management

There is currently no cure for HJMD, and treatment is primarily supportive. Regular ophthalmological evaluations are recommended to monitor vision changes. Low vision aids and rehabilitation can help affected individuals maximize their remaining vision. Genetic counseling is advised for affected families to understand the inheritance pattern and risks for future offspring.

Prognosis

The prognosis for individuals with HJMD varies. While hair abnormalities are usually stable, vision loss is progressive and can lead to significant visual impairment. However, the rate of progression and degree of vision loss can vary among individuals.

Research Directions

Research is ongoing to better understand the pathophysiology of HJMD and to explore potential therapeutic interventions. Gene therapy and other molecular approaches are areas of active investigation.

Related Pages

• Macular dystrophy
• Genetic disorders
• Autosomal recessive inheritance