Morquio's syndrome

  • Mucopolysaccharidosis 4; Brailsford syndrome.

INCIDENCE

  • One of the mucopolysaccharide abnormalities is referred to as Morquio's syndrome.
  • The metabolism of the mucopolysaccharides, which are complex sugars, requires a wide variety of enzymes in order to function properly.
  • There is a collection of conditions known as the mucopolysaccharides, and each of these conditions is characterized by a unique enzyme deficiency.
  • These effects are widespread and have an impact on a variety of organs and tissues throughout the body.
  • The accumulation of mucopolysaccharides in various organs is the primary source of the problem, as this is what causes the symptoms that are experienced.
  • Morquio syndrome affects both males and females equally, and it occurs in approximately one in one hundred thousand live births.
  • It would appear that there are two subtypes of Morquio's syndrome, one of which is more mild than the other but which shares the same signs and symptoms as the other.

HISTORY

  • In his initial account, Morquio described a family in which the affected child's parents as well as the child's grandparents shared a close relationship with one another.
  • This provided the first piece of evidence that pointed to the genetic cause of the disease.
  • Morquio's syndrome is now recognized as one of the mucopolysaccharide diseases, thanks to the advancement of biochemical and genetic knowledge.

CAUSATION

  • Morquio's syndrome is passed down through generations in an autosomal recessive manner.
  • Keratan sulfate is the name of the complicated sugar that plays a role in this particular mucopolysaccharide disease.
  • The urine of many children diagnosed with Morquio syndrome contains an abnormally high concentration of this substance, while the urine of other children with the condition does not contain any of this substance at all.
  • However, a deficiency of the enzyme that is involved in the metabolism of keratan sulphate can be found through laboratory testing in every patient who has this condition.
  • Chorionic villus sampling and amniocentesis are both methods that can be used for prenatal diagnosis.

CHARACTERISTICS

  • Normal growth and development occur prior to birth, and this pattern maintains itself throughout the first few months of a newborn's life.
  • However, by the time they are approximately 18 months old, the following characteristics start to become obvious.
  • The rate at which an individual's weight and height develops begins to slow down around the 18-month mark and continues for the rest of their lives.
  • At the age of five years, there is no longer any possibility of further growth, and the final height rarely reaches more than 32 inches (80 cm).
  • Alterations to the skeleton: the spine and chest become severely deformed, exhibiting a marked kyphosis and scoliosis, which means that the spine is twisted both forwards and sideways.
    • The ribcage is relatively short and broad, and the base of the ribs have an outwardly flared appearance.
    • The breastbone is very prominent, which contributes to the overall appearance of having a pigeon chest.
    • As a result of the upper vertebrae not developing as they should have, the neck appears to be abnormally short.
    • If this portion of the spine does not develop properly, it can eventually cause compression of the spinal cord, which manifests as neurological signs and symptoms in the limbs.
    • These signs and symptoms can begin at any age.
  • Limbs: the arms are relatively long, and all of the joints are loose, with particular laxity in the wrists and fingers.
    • The general lack of growth causes the legs to be short, and many people also have knock knees and flat feet.
  • Both the primary and secondary sets of teeth have enamel that is abnormal.
    • Because there is not enough enamel to protect the teeth, infections can spread easily, and tooth decay is an additional, excruciating problem.
  • Children who have Morquio's syndrome have an increased risk of developing deafness, which is, once again, a direct consequence of the accumulation of the particular complex sugar that is associated with the disease.
  • Some children are born with heart problems called congenital heart defects.
    • The failure of the aorta to develop normally is the most common type of problem.
  • Eyes: clouding of the cornea, a common occurrence in all of the mucopolysaccharide diseases, is frequently seen in children who have Morquio's syndrome.
  • As a result of the normal development of their intelligence, children with this syndrome are able to make progress through typical educational methods, with the exception that they are limited only by their physical capabilities.
  • The development of secondary sexual characteristics is completely normal.

MANAGEMENT IMPLICATIONS

  • Spinal issues: abnormalities in the upper cervical vertebrae frequently give rise to compression of the spinal cord.
    • This can lead to a variety of painful symptoms.
    • This is due to the abnormalities in the vertebrae themselves as well as the laxity of the ligaments in this part of the body, which is similar to the lax ligaments that surround other joints in the body.
    • Both of these factors contribute to the condition.
    • This compression causes tingling sensations and leg weakness, both of which are felt in the lower extremities.
    • In the absence of appropriate treatment, paralysis may develop.
    • This condition can be avoided or treated by fusing the vertebrae in the spine that are affected.
    • Caregivers of children who have Morquio syndrome should be aware that this complication can occur and should be alerted to the possibility by complaints of increasing weakness in the legs and/or increased difficulty in walking.
    • Caregivers should be aware that this complication can occur and should be alerted to the possibility by complaints.
    • The leg and arm muscles can be strengthened through physiotherapy, which can make movement more comfortable and easier.
    • This will also reduce the strain that is placed on joints, which have ligaments that are not very strong.
  • Being of short stature will present challenges when using equipment at school and at work.
  • When the child with Morquio's syndrome reaches the age where they will be attending secondary school, chairs and tables that have been specially adapted will be of assistance.
  • Stairs and lengthy hallways that need to be navigated throughout the course of a school day can also present challenges.
  • When assisting a Morquio child in maximizing their potential to profit from the educational system, all of these considerations need to be kept in mind.
  • Because of the unusual body shape, finding clothing that fits properly can also be challenging. Handmade clothing should be worn if at all possible because it is the most comfortable option; additionally, if the conditions are met, this can be an interesting hobby for both children and adults.
  • Prospects for employment will be contingent on the availability of jobs that are suitable for people of such a short stature, in addition to taking into account other difficulties, such as deafness and possibly poor vision.
  • Hearing needs to be tested on a regular basis. Hearing aids can be helpful for people with any kind of loss.
  • Tooth decay needs to be treated effectively by having routine dental care performed and, if necessary, by having crowns or dentures installed.

THE FUTURE

  • Complications with the heart and the nervous system lower the life expectancy of a child who has Morquio's syndrome.
  • These frequently result in premature death, typically in the twenties of the affected individual.
  • In children who have Morquio's syndrome in its most severe form, the child will present with the situation described above.
  • The more manageable form of Morquio's syndrome is associated with a greater likelihood of survival.