Introduction
IVIC syndrome, also known as Instituto Venezolano de Investigaciones Cientificas syndrome or oculo-oto-radial syndrome, is a rare autosomal dominant limb malformation genetic disorder. This disorder was first discovered in 1980 by Arias et al. This disorder may affect an individual's normal growth and development, such as difficulty hearing.
What Is IVIC Syndrome?
An IVIC syndrome is a genetic condition that is characterized by upper limb anomalies (carpal bone fusion, radial ray defects), congenital hearing loss, and external ophthalmoplegia. The symptoms can be visible at birth and affect both males and females.
What Causes IVIC Syndrome?
IVIC syndrome is caused by a mutation in the SALL4 (splat-like transcription factor 4) gene. The SALL4 gene is part of the SALL family gene group. These genes help in making the proteins that tissues and organ form during embryonic development. The SALL protein attaches to a specific part of the DNA (deoxyribonucleic acid) and controls the gene's activity. For example, the SALL4 gene helps in the development of the limbs, and nerves, and controls eye movement.
A genetic mutation is when the DNA sequence changes, creating a permanent gene change that affects average growth and development. The Okihiro syndrome or Duane-radial ray syndrome is also linked with IVIC syndrome. It is also a disorder related to a mutation in the SALL4 gene. This disorder affects the eyes and bone abnormalities.
What Are the Symptoms of IVIC Syndrome?
The symptoms of this condition include the following:
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Radial Dysplasia - Also known as radial club hand, it is a condition in which a child is born with a short or missing radial bone. Depending on its type, it may show symptoms like a short radius and a wrist slightly turned, and in severe cases, there is no radius, and the wrist is more turned in.
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Congenital Hearing Loss - It means that hearing loss is present at birth.
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External Ophthalmoplegia - It is a condition that causes weakness of the eyes. It may show symptoms like blurry vision, difficulty moving both eyes, droopy eyelids, and lifting the chin to see.
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Short Thumb - Also known as brachydactyly type D, it is a condition in which one of the thumbs is relatively shorter, rounder, and broader nail bed as compared to the other.
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Thrombocytopenia - It is a condition in which the platelet count is very low. It may show symptoms like easy bruising, prolonged bleeding, fatigue, and an enlarged spleen.
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Leukocytosis - It is a condition in which the level of white blood cells is higher than normal. It may show symptoms like fever, night sweats, rashes, and difficulty breathing.
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Carpal Bone Hyperplasia - It is a condition in which one or more carpal bones are underdeveloped, such as wrist deformity.
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Additional Symptoms - Some of the additional symptoms include limited movement of the elbow, scoliosis (sideway curvature of the spine), anal atresia (a condition in which the rectal or anal opening is absent at birth), and hypoplasia of the deltoid muscle.
How is IVIC Syndrome Diagnosed?
It is diagnosed by going through specific steps. Firstly the doctor will clinically examine the patient, thoroughly evaluate the patient’s medical history, and see the symptoms the patient is experiencing. Next, an imaging test like an X-ray and a genetic test is advised to confirm the diagnosis.
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X-ray - It uses high electromagnetic radiation that helps in creating a clear picture of the bones. It is a quick and simple procedure; the X-ray beams at the body and absorbs in different amounts. In IVIC, it helps in detecting underdeveloped bones like carpal bones.
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Genetic Testing - It examines the DNA (deoxyribonucleic acid), a database that carries instructions for the body’s functions. It is always informed before genetic testing that, in some cases, the negative result does not confirm the diagnosis, and the test can be performed again. The blood test is done by a healthcare expert who takes the blood from the arm’s vein, and the sample is sent to the laboratory for further testing. Genetic testing helps in confirming the diagnosis of piebaldism.
How Is IVIC Syndrome Managed?
To date, there is no permanent treatment for this condition as it is caused by a genetic mutation. However, the symptoms can be neutralized by focusing the treatment on them. For example, thrombocytopenia can be treated by blood transfusion (the lost blood is replaced by transfusing packed red blood cells) and medications like corticosteroids to boost platelet count. Radial dysplasia can be treated depending on the severity of changes. Some options include exercises, giving a cast to stretch the arm, and surgery to align the wrist.
Along with these, genetic counseling helps the family to understand the condition better. The genetic counselor will detail how likely a family member has the chance of getting IVIC syndrome.
What Are the Possible Complications of IVIC Syndrome?
Some possible complications that can occur due to IVIC syndrome include the following:
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In infants and young children, it may cause organ dysfunction.
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Many patients with IVIC syndrome have bone deformities, but in some cases, it may lead to severe deformities like spinal curvature.
Conclusion
IVIC syndrome is a rare congenital genetic disorder that can lead to hearing loss and bone deformity. In most cases, the symptoms are visible from birth, so diagnosing it is not that hard. A proper physical, along with genetic testing, helps in confirming the condition. As this condition occurs due to genetic mutation, there is no permanent cure, but if the symptoms are treated, it may help an individual live a better life. The family’s knowledge about this condition is very important, so the doctor will always advise the whole family to take genetic counseling as it will help in understanding the IVIC syndrome more clearly.
