About ichthyosis spastic neurologic disorder mental retardation

What is ichthyosis spastic neurologic disorder mental retardation?

Sjogren-Larsson syndrome is an inherited disorder characterized by scaling skin (ichthyosis), mental retardation, speech abnormalities, and spasticity. Affected infants develop various degrees of reddened skin with fine scales soon after birth. After infancy, the skin loses its redness and dark scales often appear on the neck and under the arms. Additionally, larger plate-like thick scales may develop on the lower legs. Developmental delay, speech abnormalities and seizures may accompany skin symptoms. Spasticity in the legs typically impairs motor ability and walking. Many children with this disorder have glistening white dots or degeneration of the pigment in the retina of the eye.

What are the symptoms for ichthyosis spastic neurologic disorder mental retardation?

The first sign of Sjögren-Larsson syndrome is often preterm birth. Apparent at birth, the ichthyosis associated with SLS often starts as thickened skin that is yellow-brown in color (hyperkeratosis). This thickened skin eventually progresses to full scaling, especially at the neck, lower abdomen, and underarms, groin, and back of knees (flexures). Unique to SLS is the itchy characteristic of the skin (pruritis).

The second feature of SLS is the stiffening of the muscles (spastic paresis). This affects the legs more often than the arms. Some individuals with SLS can walk without support, but as the stiffening worsens over time many individuals opt to use a wheelchair.

The other main clinical feature of SLS is intellectual disability. Most patients reach an average developmental age of 5-6 years of age.

Other features that could be seen include seizures, speech difficulty, short stature, spinal abnormalities (kyphoscoliosis), smaller head and brain (microcephaly), numbness in the hands and feet (peripheral neuropathy), widely spaced teeth, under-formed enamel of the teeth, widely spaced eyes, and uncontrolled movements of the eyes (nystagmus).

The symptoms of the condition can vary, even within families. However, Scaling skin (ichthyosis), intellectual disability, and Muscle stiffness (spastic paresis) are always seen. The average lifespan for affected males and females is 15 years and 26 years, respectively.

What are the causes for ichthyosis spastic neurologic disorder mental retardation?

The gene that is altered in patients with Sjögren-Larsson syndrome is the aldehyde dehydrogenase 3A2 (ALDH3A2) gene. Genes provide instructions for creating proteins that play a critical role in many functions of the body. When a mutation of a gene occurs, the protein product may be faulty, inefficient, or absent. Depending upon the functions of the particular protein, this can affect many organ systems of the body, including the brain.

Changes (mutations) in the ALDH3A2 gene result in a lower than normal amount of an enzyme (fatty aldehyde dehydrogenase). A lower amount of this enzyme leads to the scaly and itchy skin and other features seen in Sjögren-Larsson syndrome.

SLS is an autosomal recessive condition. Most genetic diseases are determined by the status of the two copies of a gene, one received from the father and one from the mother. Recessive genetic disorders occur when an individual inherits two copies of an abnormal gene for the same trait, one from each parent. If an individual inherits 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 altered gene and 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 is 25%. The risk is the same for males and females.

Parents who are close blood relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.

What are the treatments for ichthyosis spastic neurologic disorder mental retardation?

There is no cure for Sjögren-Larsson syndrome. Treatment focuses on treating symptoms as they appear and may require multiple different specialists to help address them. A comprehensive team to care for children with SLS might include specialists who help with problems of the brain and central nervous system (neurologists), specialists who assess and treat problems with the skin (dermatologists), specialists who assess and treat eye problems (ophthalmologists), specialists who assess and treat problems of the skeleton and associated muscles and joints (orthopedists), and specialists who help with movement problems (physiotherapists).

Diets low in long-chain fats, such as oils, fish, nuts, avocados, and meat, and supplemented with medium-chain fats (triglycerides), such as dairy products and coconut oil, have been associated with skin improvement for some patients. Other means of diminishing scaling of the skin includes applying keratolytic or urea-containing lotions or creams.

While there is no cure for the muscle stiffness, physical therapy may help with movement. Other means in assisting movement might include bracing and support.

Individuals with SLS will likely benefit from special education services in light of their intellectual disability. Speech and language therapy has shown some benefit in improving language performance and augmented communication skills.

Genetic counseling is recommended for affected individuals and their family members.

What are the risk factors for ichthyosis spastic neurologic disorder mental retardation?

Ichthyosis spastic neurologic disorder mental retardation (ISNDMR) is a rare genetic disorder that affects multiple systems in the body, including the skin and muscles. People with ISNDMR have abnormal muscle tone and stiffness, as well as the decreased movement of their arms and legs. They also have difficulty coordinating their movements and have poor muscle strength.

Because of these symptoms, people with ISNDMR often have trouble feeding themselves and may need to be fed through a tube. They may also experience seizures or other neurological problems, such as intellectual disability (mental retardation).

The cause of ISNDMR is unknown, but it's thought to be caused by an abnormality in chromosome 17 that affects how genes are expressed in the body.

A person with ISNMR can have the following risk factors:

1. Ichthyosis: This is the most common feature of ISNMR. It causes dry, scaly skin that can be red and cracked.

2. Spasticity: This is a condition characterized by increased muscle tone or stiffness that causes involuntary movements, such as muscle spasms or tremors.

3. Neurologic abnormalities: This means there are problems with how your brain works or functions properly. These include seizures, intellectual disabilities (mental retardation), developmental delays (meaning your child isn't reaching milestones at an appropriate pace), and vision problems like blindness or loss of sight due to cataracts (clouding of the lens).

5. The presence of more than 30 skin tags or plaques on the body at birth

6. Muscle stiffness in addition to the other symptoms listed above (not just limited to stiffness in the arms and legs)

Symptoms
Stiffness and cramping in the joints (especially the knees),Constipation due to impaired nerve function in the digestive tract,Poor muscle tone and coordination, which can lead to difficulties with walking and other motor skills
Condition
Ichthyosis vulgaris,Netherton syndrome,Hypertrophic pulmonary osteoarthropathy (HPA),Nail pitting,Atopic dermatitis
Drugs
Gabapentin,Lamotrigine,Topiramate,Valproate,Zonisamide

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