Overview
Isolated congenital onychodysplasia (ICO) is a rare condition that affects the nails, most often the nails of the fingers. It is sometimes called 'congenital nail dysplasia' or 'Iso-Kikuchi syndrome,' named after the doctors who first described it. In this condition, one or more nails grow in an abnormal way from birth or very early in life. The nails may be very small, missing, split, curved, or have an unusual shape or texture. The little finger (fifth finger) is most commonly affected, but other fingers can be involved too. Toenails are rarely affected. The condition is present at birth or becomes noticeable in the first months of life. It is called 'isolated' because it affects only the nails and is not linked to problems with other organs or body systems. Most people with ICO are otherwise healthy. The underlying cause is not fully understood, but it is thought to involve abnormal development of the nail bed and surrounding tissue during pregnancy. There is no cure for isolated congenital onychodysplasia, but the condition is generally not painful or dangerous. Treatment focuses on managing the appearance of the nails and preventing any discomfort or infection. In some cases, minor surgical procedures can improve the look and function of the affected nails. Regular follow-up with a dermatologist or hand specialist is recommended.
Key symptoms:
Abnormally small nails on one or more fingersMissing nails on one or more fingersSplit or divided nailsCurved or pincer-shaped nailsNails with an unusual texture or ridgesNails that do not grow normallyNarrow or underdeveloped nail bedNails that partially separate from the nail bedDiscoloration of affected nailsAsymmetric nail involvement (one hand more than the other)
Clinical phenotype terms (22)— hover any for plain English
Sporadic
Usually appears on its own, not inherited from a parent
Neonatal
Begins at or shortly after birth (first 4 weeks)
Treatments
No FDA-approved treatments are currently listed for Isolated congenital onychodysplasia.
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Specialists
View all specialists →No specialists are currently listed for Isolated congenital onychodysplasia.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Isolated congenital onychodysplasia.
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Questions for your doctor
Bring these to your next appointment
- Q1.Which fingers are affected and why do some nails look different from others?,Do I need any genetic testing to confirm the diagnosis or rule out other conditions?,Is there any treatment that could improve the appearance or function of the affected nails?,What signs of infection should I watch for, and when should I seek medical attention?,Will the nail abnormalities stay the same, or could they change as my child grows?,Are there any other specialists I should see, such as a hand surgeon or plastic surgeon?,Is there a risk that other family members or future children could be affected?
Common questions about Isolated congenital onychodysplasia
What is Isolated congenital onychodysplasia?
Isolated congenital onychodysplasia (ICO) is a rare condition that affects the nails, most often the nails of the fingers. It is sometimes called 'congenital nail dysplasia' or 'Iso-Kikuchi syndrome,' named after the doctors who first described it. In this condition, one or more nails grow in an abnormal way from birth or very early in life. The nails may be very small, missing, split, curved, or have an unusual shape or texture. The little finger (fifth finger) is most commonly affected, but other fingers can be involved too. Toenails are rarely affected. The condition is present at birth or
How is Isolated congenital onychodysplasia inherited?
Isolated congenital onychodysplasia follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Isolated congenital onychodysplasia typically begin?
Typical onset of Isolated congenital onychodysplasia is neonatal. Age of onset can vary across affected individuals.