Osteopetrosis

What is Osteopetrosis?

Osteopetrosis is a congenital condition that is characterized by weak bones, higher bone density and unusual skeletons. Osteopetrosis occurs as result of a person inheriting either dominant or recessive genetic traits from both parents. This condition affects both male and female and some forms of osteopetrosis are more common in children for example malignant infantile or autosomal recessive osteopetrosis. Autosomal dominant or adult type affects more men than female.

Osteopetrosis

Types

There are three forms of osteopetrosis:

  • Autosomal dominant or Adult
  • Malignant infantile or autosomal recessive osteopetrosis
  • Mild autosomal recessive.

Autosomal recessive

 This form of osteopetrosis is very severe and begins from birth. It is caused when an individual inherits one normal gene from one parent and a defective gene from another parent. The affected individual shows no symptoms unless they inherit defective genes from both parents.

Autosomal dominant

It is a mild type of Osteopetrosis and is only diagnosed in adulthood. It is caused when an individual inherits genes from both affected parents that are dominant over the normal genes.

Mild Autosomal Recessive

It is a less severe form of Osteopetrosis and usually affects children below the age of 10. It is caused when an individual inherits one normal gene from one parent and a defective gene from another parent. The affected individual shows no symptoms unless they inherit defective genes from both parents.

Causes

Osteopetrosis is a congenital condition and is caused when defective genes are transmitted from infected parents to the child.

Defective genes

Osteopetrosis occurs when you either inherit dominant or recessive traits from both parents. In dominant condition, a copy of the disease gene from either mother or father is dominant over the normal cells causing this condition. The affected parents can transmit this condition to the offspring at only 50 % chance per pregnancy irrespective of the gender of the child. The adult form of osteopetrosis contains dominant genetic traits.

In recessive condition, people usually do not show any symptoms unless they inherit defective genes from each of the parents. If you acquire one gene for this condition from one parent and another normal gene from another parent, you are a carrier of the disease and you show now symptoms.

The following forms of osteopetrosis are inherited as a recessive disorder:

  • Mild autosomal recessive
  • Malignant infantile or autosomal recessive osteopetrosis.

Symptoms

Symptoms of this disorder will depend on the type of osteopetrosis

Autosomal recessive osteopetrosis

  • Some patients usually have unusual big head
  • Accumulation of fluid in skull – cerebrospinal fluid (CSF)
  • Have eyes that seem widely spaced
  • Have crossed eyes
  • Cause blindness to some patients
  • Cause atrophy of the retina; it appears wasted
  • Complete loss of hearing in some patients
  • Some patients can acquire infections such as urinary tract infections as well as sepsis and pneumonia
  • Causes delayed development of psychomotor muscles in some patients, which affects coordination
  • Abnormal enlargement of their liver and spleen.
  • Painful tooth decay
  • Causes anaemia
  • Fractures
  • Unusual hardening of some bones.

Autosomal dominant adult type

  • Unusual hardening of some bones
  • Patients develop fractures in long bones and ribs
  • Causes inflammation in the lower jaw bone
  • Higher density of cranial bones
  • Some patients can develop dental abscess
  • Some patients can develop chronic inflammation of mucous membrane
  • Some patients can develop anaemia
  • Unusual growth of the liver and spleen.

Mild autosomal recessive

  • Vision impairment
  • Acute tooth decay
  • Some patients can develop chronic inflammation of mucous membrane
  • Some patients’ baby tooth remains intact
  • Dental problems
  • Facial paralysis
  • Some patients can develop anaemia
  • Unusual growth of the liver and spleen
  • Gradual weakening of eye nerves (optic atrophy)
  • Poor formation of tooth crown
  • Reduces number of blood platelets
  • Some patients may lack all the blood cells.

Diagnosis

Your doctor will use different tests to diagnose and find out additional information about other problems related to osteopetrosis. These tests may include blood tests, vision and hearing, magnetic resonance imaging (MRI) and computerized axial tomography (CAT) scans.

Treatment

Treatment of osteopetrosis depends on its form. The following treatment options can be used by your doctor:

Bone marrow transplant

This is a method used to replace damaged bone marrow with healthy bone marrow stem cells. There are three types of bone marrow transplants your doctor can conduct:

Umbilical cord blood transplant

A doctor removes stem cells from a child’s umbilical cord immediately after birth. The umbilical cord blood cells in babies are not yet fully developed and this requires careful correct matching to avoid further complications.

Allogeneic bone marrow transplant

The doctor can remove stem cells from donors .The doctor must conduct tests to determine whether your genes and those of the donor match.

Autologous bone marrow transplant

The doctor removes stem cells from your body. These stem cells are then returned in your body to make new blood cells after undergoing some medical interventions.

Medications

The following are some drugs your doctor will prescribe to you to help in treating the symptoms of osteopetrosis:

Prednisolone

It is a type of Corticosteroids drug and it is used to increase the count levels of platelets and enhance blood cells in your body.

Calcitriol

This is a type of vitamin D drug. It is used to help your body utilize more of calcium in order to develop strong bones and treat bone diseases.

Tips to help you Prevent

  • As a parent make sure your family consumes food rich in calcium and vitamin D to help the family develop healthy and strong muscles. You can eat the following foods: soya beans, milk and other dairy products, nuts, fish, vegetables such as cabbage and broccoli. You can also get vitamin D by exposing yourself to sunlight.
  • Parents should take their children for Orthopaedic care to assist them learn motor skills. This will also help manage a fracture in their bones.
  • Visit your dentist regularly for checkups to help you prevent dental infections. Brush your teeth often at home to make your teeth strong and healthy.
  • Visit the optician frequently for eye checkups to prevent eye infections.

Reference List

  1. Osteopetrosis. https://rarediseases.org/rare-diseases/osteopetrosis/
  2. Autosomal recessive osteopetrosis. http://adc.bmj.com/content/83/5/449
  3. Osteopetrosis. https://www.niams.nih.gov
  4. Osteopetrosis. http://www.aafp.org/afp/1998/0315/p1293.html

Leave a Reply

Your email address will not be published.