Description
| Spondyloepiphyseal dysplasia congenita (SEDC) is an inherited bone growth disorder that results in short stature (dwarfism), skeletal abnormalities, and problems with vision and hearing. This condition affects the bones of the spine (spondylo-) and the ends (epiphyses) of long bones in the arms and legs. New cases of SEDC affects one in 100,000 live births. The disorder affects males and females in equal numbers. |
Symptoms
Clinical signs of SEDC are short trunk dwarfism, barrel-chested, myopia (near-sightedness), retinal detachment, knees may be misaligned, decreased hearing, cleft palate, and flat facial features. The spine may be curved, cervical spinal compression, short neck, clubfoot, poorly formed femur heads, and instability of the cervical spine at C1 and C2. Clubfoot and cleft palate will need to be surgically repaired.
A person may have some, but not necessarily all of the above symptoms.
Intelligence is usually unaffected.
Genetics
SEDC is a random genetic mutation. SEDC is usually sporadic and is due to the chance occurrence of a genetic mutation. It is the result of a genetic defect in encoding type II collagen (COL2A1). Note that this is a purely random occurrence and that there is nothing either parent did to cause this genetic change.
SEDC is an autosomal dominant inheritance. When a person has SEDC, he/she has a 50% chance of passing the gene onto a child.
Is Intelligence affected?
People with SEDC usually have normal intelligence.
Expected Height
Height can vary. adult height ranges from 36″ – 67″ (90cm – 167.5cm).
General Medical Care
An evaluation of the C1 and C2 should be done to detect odontoid hypoplasia; spinal fusion may be indicated. Even though a spinal fusion may not be needed, lax ligaments in the neck could lead to spinal injury during anesthesia, contact sports, and car accidents.
Regular eye exams should be done by an ophthalmologist to evaluate for near-sightedness and detached retinas.
Hearing should be checked and ear infections should be closely monitored. Tubes may need to be placed in the ear.
Symptoms such as a clubfoot or cleft palate may need to be corrected.
During anesthesia, there are risks related to cervical spine instability, lung capacity, and small airways. Anesthesia should NOT be performed until these things have been evaluated.
Orthopedic care may be needed to evaluate hip, spinal, and knee complications. Hip replacement is sometimes warranted in adults. Additionally, due to poorly developed type II collagen, the person may experience arthritis.
You should always check with your medical doctor to evaluate your particular health care needs.
General Precautions
Due to neck instability, persons with SEDC should exercise caution to avoid activities/sports that could result in trauma to the neck or head.
During anesthesia, there are risks related to cervical spine instability, lung capacity, and small airways. Anesthesia should NOT be performed until these things have been evaluated.
More Information
KSG website can not keep track of the rapidly changing science! We suggest you visit the following sites for the most recent information:
LPA Medical resource center Kniest page: is an in-depth reference guide to the around 300 different types of dwarfism, intended not just for the lay person, but for medical professionals as well. The MRC also contains information about anesthesia, surgeries and procedures, common questions and a Frequently Asked Questions (FAQ).
Online Mendelian Inheritance in Man (OMIM) Kniest Page: MedlinePlus is an online health information resource for patients and their families and friends. It is a service of the National Library of Medicine (NLM), the world’s largest medical library, which is part of the National Institutes of Health (NIH).
Search https://medlineplus.gov/ . MedlinePlus is an online health information resource for patients and their families and friends. It is a service of the National Library of Medicine (NLM), the world’s largest medical library, which is part of the National Institutes of Health (NIH).
Recent Research
Search Pubmed for recent articles on Kniest Dysplasia. PubMed® comprises more than 36 million citations for biomedical literature from MEDLINE, life science journals, and online books.
