What is the disease?
Mucolipidosis Type IV (ML4) is a autosomal recessive genetic disorder that is a result of the mutation of the MCOLN1 gene located on Chromosome 19. This mutation results in a lysosomal storage disease in which there is inability of the cells to produce certain enzymes required for the breakdown of specific compounds.
The gene that the mutation occurs in, MCOLN1, was first independently discovered in 1974 by Dr. Bach of Hadassah Medical Center in Israel. This led to the discovery of ML4. In this disease both lipids and mucopolysaccharides are not broken down and therefore accumulate in the cells disrupting their normal functions. This disorder mainly affects the brain and nervous system. This disease is usually discovered as early as the first year of life.
SYMPTOMS
- CHILDREN COULD BEGIN TO EXHIBIT COGNITIVE AND MOTOR DEVELOPMENT DELAY DURING THEIR FIRST YEAR OF LIFE
- MOST CASES HAVE SEVERE MOTOR AND MENTAL RETARDATION, BUT IT CAN BE MILD IN SOME CASES
- VISUAL ACUITY MAY BE NORMAL DURING THE BEGINNING STAGES OF THE DISORDER, BUT IT IS PROGRESSIVELY IMPAIRED BY CORNEAL CLOUDING AND RETINAL DEGENERATION
- OTHER SYMPTOMS COULD INCLUDE: HYPOTONIA-POOR MUSCLE TONE AND PSEUDO-STRABISMUS- FALSE CROSS EYES
life expectancy and incidence
LIFE EXPECTANCY IS APPROXIMATELY 45 YEARS OF AGE. there has not been any known survivors passed this age.
THE DISEASE FREQUENCY FOR THE WORLD IS 1 IN 40,000. ACCORDING TO THIS INCIDENCE RATE, APPROXIMATELY 185,816 PEOPLE HAVE BEEN DIAGNOSED WITH ML4. THE DISEASE FREQUENCY FOR THE USA IS
SURPRISINGLY, THERE IS ONE SPECIFIC POPULATION THAT IS AFFECTED BY THIS DISORDER. 70% OF PEOPLE DIAGNOSED WITH ML4 ARE JEWISH OR THEY ARE OF ASHKENAZI DECENT.
DIAGNOSIS
PARENTS SHOULD HAVE THEIR CHILDREN TESTED FOR ML4 IF THE CHILD EXHIBITS SIGNS OF EXTREMELY SLOW DEVELOPING MOTOR AND MENTAL SKILLS SUCH AS SITTING, STANDING, WALKING, AND HOLDING A CUP OR CRAYON, OR IF RETINAL DEGENERATION AND CORNEAL CLOUDING HAS CAUSED VISUAL PROBLEMS. THE DISEASE CAN SIMPLY BE TESTED FOR BY A BLOOD TEST.
DISEASE TREATMENT
CURRENTLY THERE IS NO THERAPY AVAILABLE TO PATIENTS ALTHOUGH OPTIMAL SUPPORTIVE CARE, INCLUDING PHYSICAL, OCCUPATIONAL, AND SPEECH THERAPY CAN SIGNIFICANTLY IMPROVE THE FUNCTION AND QUALITY OF LIFE OF AFFECTED CHILDREN. FAMILIES SHOULD SEEK GENETIC COUNSELING AND BE OFFERED THE OPTION OF PARENTAL DIAGNOSIS FOR FUTURE PREGNANCIES.
PROGNOSIS
- LIFE EXPECTANCY-45 YEARS
- DEPENDING ON THE SEVERITY OF THE DISEASE, SYMPTOMS COULD STAY THE SAME OR WORSEN OVER TIME
- CHILDREN DIAGNOSED WITH THIS DISEASE WILL NEVER BE ABLE TO FUNCTION FULLY ON THEIR OWN
- THEY WILL NOT BE ABLE TO PARTICIPATE IN DAILY PHYSICAL ACTIVITIES AND THEY WILL NEED TO HAVE A CONSTANT CARE TAKER