About mmr syndrome

What is mmr syndrome?

Megalocornea-mental retardation (MMR) syndrome, otherwise known as Neuhauser syndrome, is an extremely rare genetic disorder characterized by distinctive abnormalities of the eye, several degrees of cognitive impairment, and a wide variety of additional symptoms The range and severity of the symptoms varies greatly from one person to another, which has led some researchers to suggest that MMR syndrome encompasses several distinct, but similar disorders. The exact cause of the disorder is unknown. Some cases appear to follow an autosomal recessive inheritance pattern.

What are the symptoms for mmr syndrome?

Swollen glands in the neck and armpits symptom was found in the mmr syndrome condition

A characteristic symptom of all individuals affected with megalocornea-Intellectual disability syndrome is a distinctive eye abnormality known as megalocornea, which is the abnormal, nonprogressive enlargement of the cornea that occurs without the presence of increased pressure within the eye (glaucoma). The cornea is the clear (transparent) outer layer of the eye and has two functions – it protects the rest of the eye from dust, germs and other harmful or irritating material and it acts as the eye’s outermost lens, bending incoming light onto the inner lens, where the light is then directed to the retina (a membranous layer of light-sensing cells in the back of the eye). The retina converts light to images, which are then transmitted to the brain. The cornea must remain clear to be able to focus incoming light. Megalocornea is present at birth (congenital) and usually affects both eyes (bilateral). Although the cornea is abnormally enlarged, it is otherwise normal in structure, curvature and thickness.

Some affected individuals have additional abnormalities affecting the eyes including underdevelopment (hypoplasia) of the colored portion of the eyes (iris), abnormal “unsteadiness” of the irises during eye movements (iridodonesis) and abnormal shaping of the eye so that it does not bend light appropriately (refractive errors).These additional eye abnormalities can potentially lead to varying degrees of visual impairment.

Other characteristic features of all individuals affected with this condition include Intellectual disability and delays in the acquisition of motor skills (psychomotor delay). Most (>80%) affected individuals also experience hypotonia. Other neurologic abnormalities may be observed, including delayed speech development, poor coordination and clumsiness, seizures, hyperactivity and Involuntary movements of the face, arms and legs (limbs) and trunk consisting of slow, continual, writhing movements (athetosis) occurring in association with more rapid, jerky movements (choreoathetoid movements).

Individuals with megalocornea-Intellectual disability syndrome may also have distinctive features in the head and face area (craniofacial region). These include microcephaly, a condition that indicates that the head circumference is smaller than would be expected for an infant’s age and sex, or macrocephaly, a condition in which there is a disproportionally Large head circumference. Additional craniofacial findings may include an unusually Prominent forehead (frontal bossing), widely spaced eyes (ocular hypertelorism), downward slanting eyelid folds (palpebral fissures), vertical skin folds between the inner corners of the eyes and the nose (epicanthal folds), widening of the top part of the nose (broad nasal bridge), a long upper lip, an abnormally small lower jaw (micrognathia), a high and narrow roof of the mouth (high arched palate) and/or unusually large and/or “cup-shaped” ears.

Rare physical malformations may also be present, including abnormally long and/or permanently flexed fingers (camptodactyly), abnormal sideways curvature of the spine (scoliosis), abnormal forward curvature of the spine (kyphosis) and heart defects. Patients have also been reported with very flexible joints (joint hyperlaxity).

Additionally, affected individuals may experience primary hypothyroidism where the thyroid gland does not produce appropriate levels of hormones. These hormones are required for many bodily functions including growth and metabolism. Some affected individuals experience Growth delays ultimately resulting in short stature. Recurrent infections have also been reported in some patients.

What are the causes for mmr syndrome?

The exact cause of megalocornea-intellectual disability syndrome is unknown. However, cases reported in the literature are consistent with an autosomal recessive inheritance pattern or new (de novo) genetic changes (variants) that were not inherited from parents.

Recessive genetic disorders occur when an individual inherits a non-working gene from each parent. If an individual receives one working gene and one non-working 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 non-working 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 working genes from both parents is 25%. The risk is the same for males and females.

Although megalocornea intellectual disability syndrome is suspected to have an underlying genetic cause, genetic variants in specific genes have not been shown to cause the condition.

What are the treatments for mmr syndrome?

Treatment is directed towards the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, surgeons, physical therapists and specialists who assess and treat eye problems (ophthalmologists), neurological disorders (neurologists), skeletal disorders (orthopedists) and heart problems (cardiologists) may need to systematically and comprehensively plan an affected child’s treatment.

In affected infants or children with megalocornea, iris abnormalities and/or refractive errors, corrective glasses, contact lenses, surgery and/or other supportive techniques may be used to help improve vision.

In some affected infants and children with neuromuscular abnormalities, physical therapy and/or other supportive therapies may be used to help improve motor skills and coordination. In some patients, treatment with anticonvulsant drugs may help to prevent, reduce or control seizures potentially occurring in association with the disorder. In some patients, hormone replacement therapies can be initiated to treat hypothyroidism and normalize thyroid hormone levels.

Early intervention is important to ensure that children with this syndrome reach their full potential. Special services that may be beneficial to affected children may include special education, special social support and other medical, social, and/or vocational services. Genetic counseling is recommended for affected individuals and their families.

What are the risk factors for mmr syndrome?

Megalocornea-mental retardation syndrome or the MMR syndrome is a rare genetic disorder that affects the shape of the cornea and the way a child's brain develops. People who have this disorder are born with eyes that are larger than normal, which can cause vision problems. In addition, this condition causes mental disabilities that range from mild to severe.

The cornea is the clear, outermost layer of the eye. It helps to focus light entering the eye onto your retina, which then sends images to your brain.

MMS causes the cornea to be unusually misshapen or too thin. This can cause poor vision, especially in bright light.

People with MMS also have severe learning disabilities and problems with movement and coordination—these issues often get worse as they get older.

The common risk factors include:

1. Having two copies of the same defective gene (autosomal recessive inheritance)

2. Being born to parents who each have one copy of the defective gene (autosomal recessive pedigree)

3. Having a parent with another autosomal recessive genetic disorder that causes similar symptoms (consanguineous marriage)

4. Having a parent who has been exposed to radiation or certain chemicals during pregnancy.

5. If you have a family history of MMS, you're more likely to develop it yourself.

6. If you have cystic fibrosis, you're more likely to develop MMS.

7. If you have Down syndrome, you're more likely to develop MMS.

8. If you have Turner syndrome (in which only one X chromosome is present), you're more likely to develop MMS.

Sore throat,Runny nose,Coughing,Swollen glands in the neck and armpits,Low-grade fever
Diabetes,Kidney disease,Rheumatoid arthritis,Other autoimmune disorders,Neurological disorders
Antidepressants and anti-seizure drugs,Antipsychotics,Anticonvulsant drugs,Immunosuppressants

Video related to mmr syndrome