Pediatric Orthopedic Surgeons treating Congenital Spine Disorders

KNIEST DYSPLASIA

Kniest dysplasia refers to an extremely rare disorder of bone growth that leads to short stature. Additionally the condition produces malformed bones and joints, and skeletal abnormalities. It’s diagnosed only once out of every 1 million births.

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Kniest Dysplasia

Kniest dysplasia is a rare genetic skeletal disorder classified as a type II collagenopathy. It is characterized by short stature, joint deformities, and other skeletal abnormalities. It results from mutations in the COL2A1 gene. This gene encodes type II collagen, a critical structural protein in cartilage, connective tissues, and the vitreous of the eyes.

Understanding the causes of Kniest dysplasia is particularly relevant in genetic testing, pediatric orthopedic conditions like juvenile osteoporosis, and knee pain in children, as well as pediatric care in communities like Dallas, TX. Below. The following outlines the causes of Kniest dysplasia, focusing on its genetic basis and contributing factors.

Primary Cause of Kniest Dysplasia: Mutations in the COL2A1 Gene

Genetic Basis:
Kniest dysplasia is caused by dominant mutations in the COL2A1 gene, located on chromosome 12q13.11-q13.2. This gene provides instructions for producing type II collagen. This is essential for cartilage strength and flexibility, which forms the framework for developing bones and joints. Mutations disrupt the collagen’s triple-helix structure, leading to abnormal cartilage formation and weakened skeletal tissues. Common mutation types include:

Missense mutations: Alter single amino acids, impairing collagen folding.
Splice-site mutations: Affect mRNA processing, producing defective collagen.
Deletions or insertions: Disrupt the collagen protein sequence.
These mutations result in a dominant negative effect, where the abnormal collagen interferes with normal collagen function, causing the characteristic features of Kniest dysplasia, such as short limbs, a barrel-shaped chest, and joint contractures.

Inheritance Pattern:

Autosomal dominant: A single mutated copy of the COL2A1 gene from one parent is sufficient to cause the condition. Most cases (up to 80%) arise from de novo mutations, meaning they occur spontaneously in the child without a family history, rather than being inherited.
Rarely, the mutation is inherited from a parent with Kniest dysplasia or a related collagenopathy, such as Stickler syndrome, which also involves COL2A1 mutations.
Example: A child in Dallas, TX, with no family history of skeletal disorders, develops Kniest dysplasia. Genetic testing discloses that the condition was due to a spontaneous missense mutation in COL2A1.

QUESTIONS AND ANSWERS

What constitutes Kniest Dysplasia, and what causes it?

Kniest Dysplasia refers to a rare genetic disorder that falls under the broader category of skeletal dysplasia. It primarily affects the development of bones, leading to short stature, joint problems, and other skeletal abnormalities.
The cause of Kniest Dysplasia identifies a mutation of the COL2A1 gene, which provides instructions for making type II collagen, a protein crucial for cartilage and bone development. These mutations occur spontaneously and do not stem from the parents.

What are the common symptoms and challenges associated with Kniest Dysplasia in children?

Symptoms

Short Stature: Children with Kniest Dysplasia are often significantly shorter than their peers, and this short stature may be apparent from a young age.
Joint Problems: Joint abnormalities are common and can include joint contractures, hypermobility, and dislocations. These joint issues can lead to pain and mobility challenges.
Orthopedic Conditions: Many children with Kniest Dysplasia are also diagnosed with additional orthopedic conditions such as scoliosis (curvature of the spine), hip dysplasia, joint stiffness, and limb shortening. Some of these issues, like craniofacial anomalies or club foot, may be present at birth and may require surgical intervention early on. In contrast, others may only become noticeable or problematic as a child grows.
Other Health Concerns: Hearing loss is another possible complication. In some cases, it’s mild and simply needs to be monitored to ensure it doesn’t worsen over time.
Ear and Hearing Problems: Some children with Kniest Dysplasia may have hearing problems due to ear abnormalities.
Respiratory Issues: Severe cases may be associated with respiratory difficulties due to a narrow chest and reduced lung capacity.
Cleft Palate: A cleft palate, which is an opening or split in the roof of the mouth, can occur in some individuals with Kniest Dysplasia.

How do doctors manage and treat Kniest Dysplasia in children?

Children with Kniest Dysplasia

How do doctors manage and treat Kniest Dysplasia in children?
- Multidisciplinary Care: Managing Kniest Dysplasia often involves a multidisciplinary team, including pediatric orthopedic specialists, geneticists, physical therapists, and other healthcare professionals. For example, children may see:
  - An orthopedist for any bone, muscle, and joint-related issues
  - A plastic surgeon for craniofacial or hand anomalies
  - An audiologist for hearing issues
  - An ophthalmologist for vision problems
  - Physical and occupational therapists to expand physical dexterity and skill
- Symptomatic Treatment: Treatment focuses on addressing the symptoms and complications that arise. This may include surgical interventions for joint issues, therapies to improve mobility, and interventions for hearing problems or cleft palate.
- Growth Monitoring: Parents should monitor the growth of their children, and in some cases, doctors will recommend growth hormone therapy to help promote growth.
- Psychological Support: Medical professionals believe that psychosocial support helps children and families to cope with the challenges of Kniest Dysplasia, including its impact on self-esteem and quality of life.

Kniest Dysplasia is a complex condition, and the management plan must be individualized to address the specific needs and challenges of each child. Families are encouraged to work closely with healthcare providers who have experience in treating skeletal dysplasias to ensure the best possible outcomes for the child’s overall health and quality of life.

The doctors and surgeons at the Medical City Children’s Orthopedics and Spine Specialists treat children with Kniest Dysplasia. We specialize in children and adolescents.

Outlook for Children with Kniest Dysplasia

Children diagnosed with Kniest dysplasia generally have normal intelligence and can expect a typical lifespan. Many go on to pursue education, meaningful careers, start families, and enjoy fulfilling lives much like their peers. However, early-onset arthritis and joint issues are common due to skeletal differences, which may limit participation in some physical activities or sports. While certain physical challenges may arise, most children adapt well with the support of their healthcare team and family.

If you have concerns about how Kniest dysplasia may impact your child’s long-term goals or day-to-day life, we encourage you to speak directly with your healthcare provider. Personalized guidance can help you plan for and address your child’s unique needs as they grow.

Symptoms

Kniest dysplasia is a rare genetic disorder that affects bone growth and development. The severity and range of symptoms can vary widely among affected individuals. However, some of the most common symptoms of Kniest dysplasia include:

Short stature: People with Kniest dysplasia are typically shorter than average due to a shortened trunk and limbs.
Joint stiffness and pain: Kniest dysplasia can cause joint stiffness in the knees and hips, which can lead to pain and difficulty with mobility.
Early arthritis and activity limitations: Because of joint abnormalities, individuals with Kniest dysplasia may experience arthritis earlier than usual and may not be able to participate in certain activities.
Abnormalities of the spine: This condition can cause a curvature of the spine, known as scoliosis, which can worsen with age.
Facial abnormalities: Individuals with Kniest dysplasia may have a flat face, a small chin, and prominent eyes.
Hearing loss: Some people with Kniest dysplasia may experience hearing loss due to abnormalities in the ear.
Respiratory problems: In severe cases, this condition can cause respiratory problems due to a narrowed or compressed airway.
Eye problems: Kniest dysplasia can cause nearsightedness, glaucoma, or retinal detachment.

In conclusion

It’s important to note that the severity and combination of symptoms can vary widely among affected individuals. People with Kniest dysplasia may also develop other health problems. For instance, spinal cord compression, so it’s important to receive regular medical care and monitoring. If you suspect your child has Kniest dysplasia, we recommend that you see us for a proper diagnosis and management.

Diagnosis of Kniest Dysplasia

Diagnosis of Kniest Dysplasia typically involves a physical exam and a review of the patient’s medical history. In addition, imaging tests such as X-rays or MRI scans will assist in the diagnosis. Doctors also use genetic testing to confirm the presence of the COL2A1 mutation.
During follow-up visits, X-rays and other diagnostic testing may be done. The goal of continued monitoring is to identify irregularities in growth or development and to address new health issues.

Treatment

As previously written, Kniest dysplasia refers to a rare genetic disorder that affects bone growth and development. Unfortunately, at this time, a cure does not exist for this condition. Furthermore, treatment is primarily focused on managing symptoms and complications.

Treatment options can range from non-surgical approaches like bracing and physical therapy to more involved surgical procedures. For instance, spinal fusion or insertion of growing rods to help stabilize the spine as a child continues to grow. Ultimately, a collaborative care team will work closely with families to develop a personalized care plan. The plans support each child’s unique needs and promote optimal mobility and quality of life.

Some treatments that our practice recommends for individuals with Kniest dysplasia include:

Physical therapy: Physical therapy can help individuals with Kniest dysplasia strengthen their muscles, improve their range of motion, and increase mobility.
Orthopedic devices: Orthopedic devices such as braces, splints, or special shoes can help support the bones and joints. Additionally, they improve mobility, and prevent further complications.
Surgery: In some cases, surgery may help correct skeletal abnormalities or alleviate symptoms such as spinal compression or joint pain.
Pain management: Pain management techniques such as medication, heat and cold therapy, and massage can help relieve pain associated with Kniest dysplasia.
Respiratory support: Accordingly, individuals with severe Kniest dysplasia may require respiratory support to assist with breathing.

Effects of Kniest Dysplasia

Many children with Kniest dysplasia are also diagnosed with a variety of orthopedic conditions, including scoliosis, hip dysplasia, joint stiffness, craniofacial anomalies, and limb shortening. Sometimes, these conditions are present at birth and can be addressed early in life. For example, a child with a cleft palate or club foot may need surgery. Meanwhile those with mild hearing loss might simply be monitored to ensure the condition doesn’t worsen.

Collaborative Effort

It is important to work closely with a medical team experienced in managing Kniest dysplasia. By doing this, the doctors can determine the best treatment plan for each individual’s unique needs. Children with Kniest dysplasia often face a range of orthopedic challenges, including scoliosis, hip dysplasia, joint stiffness, craniofacial differences, and limb shortening. Sometimes, these conditions are noticeable at birth and can be treated early, such as a cleft palate or club foot, which may require surgery. Other issues, like mild hearing loss, might just need careful monitoring as your child grows.

Complications

In some cases, complications from Kniest dysplasia may not become apparent until later in childhood, especially those involving the spine or joints. As your child develops, doctors will keep an eye out for changes such as spinal curvature or hip and knee problems, adjusting care as needed.
Because every child’s situation is different, treatment is always tailored on a case-by-case basis.

Other complications may only become noticeable or problematic as a child grows. This is often the case with spinal deformities such as scoliosis, hip and knee issues, and increasing joint stiffness. Treatment plans are highly individualized, as every child’s needs are different. For instance, if scoliosis is present, the severity and location of the curve, as well as the child’s age and stage of growth, are all weighed before determining the most appropriate course of action.

For example, when managing scoliosis, the medical team will consider factors like the severity and location of the curve, as well as your child’s age and stage of growth, before recommending the best course of action. Regular collaboration with specialists—such as orthopedic surgeons, physical therapists, and audiologists—helps ensure your child receives comprehensive, individualized care.

Follow-Up Care After Spine Surgery

For children who have undergone spine surgery due to Kniest dysplasia, a consistent schedule of follow-up appointments is crucial for monitoring recovery and long-term spine health. We recommend the first post-operative visit within one to two weeks after surgery. Subsequent check-ups are typically scheduled at three months and again at six months following the procedure.

After these initial visits, annual evaluations with an orthopedic specialist are advised. This ongoing monitoring allows your care team to promptly identify and address any developing concerns, helping to ensure the best possible outcomes as your child grows.

Prevention

Kniest dysplasia refers to a genetic disorder caused by a mutation in the COL2A1 gene. As such, it is not preventable. However, there are several options for couples who are at risk of having a child with Kniest dysplasia:

Genetic counseling: Couples who have a family history of Kniest dysplasia or who are carriers of the COL2A1 gene mutation can consult with a genetic counselor to assess their risk of having a child with the disorder. Genetic counseling can help couples understand the inheritance pattern of Kniest dysplasia and available options for prenatal diagnosis and management.
Prenatal diagnosis: Couples who are at risk of having a child with Kniest dysplasia can opt for prenatal diagnosis. This includes procedures such as chorionic villus sampling (CVS) or amniocentesis. These tests can detect the COL2A1 gene mutation in a developing fetus and allow for informed decision-making about pregnancy management.
Assisted reproductive technologies (ART): Couples who are carriers of the COL2A1 gene mutation can consider ART options such as preimplantation genetic diagnosis (PGD) or in vitro fertilization (IVF) with donor eggs or sperm. These options can help to reduce the risk of passing on the mutation to their offspring.

It’s important to note that each case is unique. The most appropriate prevention strategies depend on various factors such as the individual’s medical history and family background. Consulting with a healthcare professional or genetic counselor can help couples make informed decisions about their reproductive options.

Rehabilitation

The time required for rehabilitation from Kniest dysplasia varies depending on the severity of the condition and the specific interventions used. In many cases, ongoing medical care and management are necessary throughout the patient’s life.

Consistent follow-up with an orthopedic physician is important, especially for individuals who have undergone spine surgery. Typically, post-surgical care involves a visit to the orthopedic surgeon one to two weeks after the procedure, followed by appointments at three and six months, and then annual check-ups to monitor progress and address any new concerns.

Because Kniest dysplasia can affect multiple body systems, a multidisciplinary approach is often recommended. Patients may be referred to a variety of specialists, including:

Orthopedists for monitoring bone, muscle, and joint health
Plastic surgeons for craniofacial or hand anomalies
Audiologists evaluate and manage hearing issues
Ophthalmologists for vision concerns
Physical and occupational therapists to support and expand physical dexterity and daily living skills

During these follow-up visits, diagnostic tools such as X-rays and other tests may be used to track growth and development. Ongoing monitoring aims to promptly identify and address any irregularities or emerging health issues, ensuring the best possible outcomes over time.

Why Choose Medical City Children’s Orthopedics and Spine Specialists

Pediatric orthopedics is a specialty of our doctors and surgeons at Medical City Children’s Orthopedics and Spine Specialists. More importantly, they understand your concerns, can answer your questions regarding your child’s condition, and know how to use their specialized knowledge to assist you. Dr. Shyam Kishan, MD, Dr. Kathryn Wiesman, MD, and Dr. Richard A. Hostin, MD, have many years of training and experience in bone, joint, and muscle care for children and young adults and can help you and your child get back to living the life you love.

Our team of pediatric spine surgeons and other specialists has more than 250 years of combined experience diagnosing and treating spine conditions in pediatric patients. That depth of expertise means your child will benefit from the collective knowledge and skill of professionals who have seen and treated virtually every type of pediatric orthopedic and spine issue.

The following are some of the many reasons why patients choose Medical City Children’s Orthopedics and Spine Specialists.

Expertise in pediatric orthopedics and spine: The team of specialists at Medical City Children’s Orthopedics and Spine Specialists is expert. As such, they specialize in the diagnosis and treatment of pediatric orthopedic and spinal conditions, ensuring the best possible care for children. With centuries of combined experience, our team is uniquely equipped to handle complex and rare cases with confidence.
Cutting-edge technology: Our practice uses the latest technology and techniques to diagnose and treat a wide range of conditions. In addition, we use minimally invasive procedures that reduce pain and promote faster recovery.
Comprehensive care: Our practice offers a full range of services, from diagnostic imaging and physical therapy to surgery. Therefore, we ensure that patients receive complete, seamless care for their orthopedic and spinal conditions.
Dedicated pediatric facilities: Medical City Children’s Orthopedics and Spine Specialists are dedicated to providing children with a safe and comfortable environment.

Resources to Support Your Family

We know that finding answers to your questions and feeling confident in your child’s care are just as important as receiving expert medical treatment. That’s why we offer a range of resources—including video, audio, and web materials—to help guide you every step of the way. Whether you’re looking for the latest information about pediatric spine conditions or practical advice to support your child at home, our Spine Program Resources are designed with families in mind.

Our board-certified physicians and fellowship-trained orthopedic surgeons use full-range treatments to treat Kniest Dysplasia. Get in touch with us today to schedule an appointment at one of our five offices in Dallas, Arlington, Flower Mound, Frisco, and McKinney, TX. – 214-556-0590.

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Footnote:

National Organization of Rare Disorders: Kniest Dysplasia

Call 214-556-0590 to make an appointment.

Comprehensive services for children from birth through adolescence at five convenient locations: Arlington, Dallas, Flower Mound, Frisco and McKinney.