About campomelic syndrome, long-limb type

What is campomelic syndrome, long-limb type?

Campomelic syndrome is a rare congenital disorder in which multiple anomalies are present. It is characterized by bowing and angular shape of the long bones of the legs, especially the tibia; multiple minor anomalies of the face; cleft palate; other skeletal anomalies such as abnormalities of the shoulder and pelvic area and eleven pairs of ribs instead of the usual twelve; underdevelopment of the trachea; developmental delay in some cases and incomplete development of genitalia in males such that they appear to be females.

What are the symptoms for campomelic syndrome, long-limb type?

Campomelic syndrome is a rare form of Skeletal dysplasia characterized by bowing and an angular shape of the long bones of the legs. Eleven sets of ribs instead of the usual twelve may be present. The pelvis and shoulder blade may be underdeveloped. The skull may be large, long and narrow. The face may appear flat with forward tilting nostrils, high forehead, small chin, and cleft palate. Babies may regurgitate formula through the nose, are susceptible to middle ear infections and frequently experience respiratory distress.

Respiratory distress due to an underdeveloped ribcage is the most serious symptom of campomelic syndrome. The lungs may not have sufficient space to grow properly due to the underdeveloped ribcage.

Other symptoms that may occur in some patients with campomelic syndrome are dislocated hips, clubfoot, underdeveloped lungs, abnormal cervical and thoracic vertebrae,and heart and kidney abnormalities.

Some individuals with campomelic syndrome have sex reversal in which they are chromosomally male but have female genitalia and reproductive system.

What are the causes for campomelic syndrome, long-limb type?

Campomelic syndrome was once thought to be inherited as an autosomal recessive genetic trait but this is no longer thought to be true. Molecular genetic research has shown that a change (mutation) in a single copy of the SOX9 gene on chromosome 17 or disturbance in the regulation of this gene causes campomelic syndrome. The regulation of the SOX9 gene is sometimes disturbed by a rearrangement of genes on chromosome 17 (translocation). It is now believed that campomelic syndrome is inherited as an autosomal dominant trait. Some families have been reported in which multiple children are affected but both parents are unaffected. This may be due to one parent having a mixture of sperm or egg cells with normal and abnormal SOX9 genes (gonadal mosaicism). As a result, one or more of this parent’s children may inherit the gene mutation and exhibit the disorder even though the parent has no apparent symptoms.

Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.

Recessive genetic disorders occur when an individual inherits the same abnormal gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the defective gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier like the parents is 50% with each pregnancy. The chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25%. The risk is the same for males and females.

Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

What are the treatments for campomelic syndrome, long-limb type?

Treatment of respiratory problems consists of mechanical or physical breathing assistance such as positive end expiratory pressure (PEEP). Orthopedic medical care including surgery may help alleviate some of the more serious bone deformities. The bowed tibiae usually straighten spontaneously.

It may be appropriate to reassign the sex of a male with female genitalia to be female.

Genetic counseling may be of benefit for patients and their families. Other treatment is symptomatic and supportive.

The Vertical Expandable Prosthetic Titanium Rib (VEPTR) was approved by the FDA in 2004 as a treatment for thoracic insufficiency syndrome (TIS) in pediatric patients. TIS is a congenital condition where severe deformities of the chest, spine, and ribs prevent normal breathing and lung development. The VEPTR is an implanted, expandable device that helps straighten the spine and separate ribs so that the lungs can grow and fill with enough air to breathe. The length of the device can be adjusted as the patient grows. The titanium rib was developed at the University of Texas Health Science Center in San Antonio.

What are the risk factors for campomelic syndrome, long-limb type?

Campomelic syndrome, long-limb type, is a rare disorder that affects the bones, muscles and cartilage. Symptoms of this condition include abnormal facial features, abnormal hand structure and abnormal joint development. It can also lead to limb deformities, such as clubfoot or curved fingers. In some cases, the affected person may have only one hand with a shortened ulna (forearm bone).

There are no known causes for the campomelic syndrome, long-limb type. However, it is thought to be genetic in nature. The condition occurs equally in males and females. It may also be linked to other conditions such as Marfan syndrome and Stickler syndrome.

Campomelic syndrome is caused by mutations in the GDF8 gene. The disorder is inherited in an autosomal dominant manner which means that only one parent needs to have the mutated gene for it to be passed on to their children.

There are several risk factors for the campomelic syndrome, long-limb type:

1. The disease can run in families. If you have a child with this condition, you have an increased chance of having another child with it too—even if you didn't have any symptoms yourself when you were younger.

2. Being male increases your risk of developing Campomelic syndrome because males are more likely than females to have an X chromosome abnormality (like having only one X chromosome instead of two).

3. Being tall increases your risk because people who are taller tend to have longer limbs than those who aren't as tall.

4. Genetic mutations related to a gene called FGF4.

5. Environmental risk factors like exposure to certain chemicals or viruses during pregnancy

Symptoms
Shortness of the arms and legs,Lower limbs that are smaller than normal,Low birth weight,An unusually short trunk (stooped posture),The appearance of bowed legs and knock knees
Conditions
Short stature (height),An unusually small head size (microcephaly),Curved fingers (camptodactyly),Abnormal curvature of the spine (kyphoscoliosis),Abnormal curvature of the spine (kyphoscoliosis)
Drugs
Azathioprine,Methotrexate,Mycophenolate mofetil (MMF),Rituximab

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