Meyahealth
HomeGeneticsGeneHYCC1 gene
Back to Gene
HYCC1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

HYCC1 gene

The HYCC1 gene provides instructions for making the protein hyccin, which is necessary for the formation of myelin and the protection of nerve impulses.

Normal Function

The HYCC1 gene provides instructions for making a protein called hyccin, which is active throughout the nervous system. Researchers believe hyccin is involved in the formation of myelin, the protective covering of nerves that promotes the efficient transmission of nerve impulses. Hyccin is also active in the lens of the eye, the heart, and the kidneys, though its specific function in these tissues remains unclear.

Health Conditions Related to Genetic Changes

Hypomyelination and congenital cataract

Variants in the HYCC1 gene cause hypomyelination and congenital cataract. Most of these variants prevent the production of any functional hyccin protein, while others, such as the Leu53Pro variant, allow for some protein production and typically result in milder symptoms.

Disruption in hyccin production impairs myelin formation, leading to neurological issues such as intellectual disability and walking difficulties. Additionally, affected individuals typically experience clouding of the lens (cataract) from birth. The combination of these neurological problems and cataracts are the hallmark features of this disorder.

Other Names for This Gene

  • DRCTNNB1A
  • FAM126A
  • HCC
  • HLD5
  • HYCC1
  • HYCCI_HUMAN

Frequently Asked Questions

Children with HYCC1‑related disease often achieve early milestones (sitting, rolling) later than peers, and walking may be delayed until 2–3 years or beyond. Speech and cognitive development can range from mild delay to moderate intellectual disability. Prompt referral to early intervention services, physical and occupational therapy, and vision rehabilitation is advised as soon as delays are noted, typically before 12 months of age, to maximize functional outcomes.
HYCC1‑related disease follows an autosomal recessive inheritance. If both parents are carriers, each pregnancy carries a 25 % chance of an affected child, a 50 % chance of a carrier, and a 25 % chance of an unaffected, non‑carrier child. Prenatal options include carrier testing, chorionic villus sampling, or amniocentesis for molecular diagnosis, and pre‑implantation genetic testing for embryos if using IVF. Genetic counseling is strongly recommended.
Diagnosis is confirmed by sequencing the HYCC1 gene, usually via a targeted gene panel for leukodystrophies or whole‑exome sequencing. A peripheral blood sample (EDTA tube) is the standard specimen. In some cases, skin fibroblast or buccal swab DNA may be used if blood is unavailable. Testing should be ordered through a clinical genetics laboratory with expertise in rare neuro‑developmental disorders.
t present, no disease‑modifying therapy exists for HYCC1‑related hypomyelination. Management focuses on supportive care: physical therapy to maintain mobility, antispasticity medications if needed, and regular ophthalmologic evaluation for cataract surgery. Research into gene‑therapy and small‑molecule chaperones is ongoing, and enrollment in clinical trials should be discussed with a neurologist.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

Meyahealth

Ⓒ 2026. All rights reserved by MEYA

About UsTerms & PolicyFAQ