About ito hypomelanosis

What is ito hypomelanosis?

Hypomelanosis of Ito is a rare condition characterized by distinctive skin changes, in which areas of the body lack skin color (hypopigmentation). These skin changes may present as patches, streaks or spiral-shaped (whorled) areas. In many cases, additional symptoms affecting areas outside of the skin also occur. There are a wide variety of symptoms potentially associated with hypomelanosis of Ito. Neurological findings such as seizures and developmental delays and musculoskeletal symptoms such as abnormal curvature of the spine (scoliosis) are commonly associated with this condition. Because of the neurological and skin symptoms hypomelanosis of Ito may be referred to as a "neurocutaneous" syndrome. However, in many cases the condition arises from genetic irregularities that are present in some cells of the body, but not in others (mosaicism). Some researchers believe that hypomelanosis of Ito does not represent a distinct disorder but rather a symptom common to a group of disorders involving genetic mosaicism.



What are the symptoms for ito hypomelanosis?

Scoliosis symptom was found in the ito hypomelanosis condition

The most distinctive finding associated with hypomelanosis of Ito is characteristic skin changes. Most affected individuals develop areas that lack skin color (hypopigmentation). Any area of the body may be involved although the scalp, palms and soles are rarely affected. Skin changes may occur as patches, streaks or spiral-shaped (whorled) areas of discoloration and may affect one side of the body (unilateral) or both sides (bilateral). Affected areas of skin are usually normal otherwise. The skin Lesions usually appear during the first year of life and remain unchanged through childhood, but may fade or darken in adulthood. Skin Lesions are not associated with Inflammation or a premalignant (verrucous) condition.

In some cases of hypomelanosis of Ito, additional non-cutaneous features may occur. It is important to note that the specific symptoms that occur vary greatly from person to person and affected children will not have all the symptoms discussed below. Because children with the characteristic skin changes of hypomelanosis of Ito and no associated abnormalities may go unreported, determining the actually frequency of associated findings is difficult. The number of affected individuals with additional symptoms has been estimated to be anywhere from 30-90 percent.

Neurological findings may occur in some cases including Seizures that occur during infancy and are often resistant to therapy, some degree of cognitive impairment, and delays in attaining milestones that require the coordination of muscular and mental activity (psychomotor impairment). In some cases, one side of the brain may be larger than the other (hemimegalencephaly).

Less often, some individuals have crossed eyes (strabismus), eyes that a spaced apart wider than normal (hypertelorism), cleft palate, cleft lip, and dental anomalies such as missing teeth (anodontia). Loss of hair usually in a patchy pattern (alopecia) may also occur. Some infants may have microcephaly, a condition that indicates that the head circumference is smaller than would be expected for age and sex; others may have macrocephaly, which indicates that head circumference is larger than would normally be expected.

A variety of Skeletal abnormalities have occurred in individuals with hypomelanosis of Ito including abnormal side-to-side curvature of the spine (scoliosis), disproportionate length of the legs (limb length discrepancy), and abnormal fixation or “locking” of the pinky in a bent position (clinodactyly). Diminished muscle tone (hypotonia) may also occur.

Additional symptoms that may affect individuals with hypomelanosis of Ito include additional eye abnormalities, deafness, overgrowth of one side of the body (hemihypertrophy), heart (cardiac) abnormalities, kidney (renal) malformations, and abnormalities of the genitourinary tract, which contains the reproductive organs and urinary system.



What are the causes for ito hypomelanosis?

The exact cause of hypomelanosis of Ito is unknown. Many cases are associated with genetic mosaicism and sporadic gene mutations. Genetic mosaicism is the term for individuals who have two distinct cell lines in the body that developed because of a gene mutation that occurred during embryonic development. The two cell lines have differences involving the chromosomes (chromosomal mosaicism).

Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated “p” and a long arm designated “q”. Chromosomes are further sub-divided into many bands that are numbered. The numbered bands specify the location of the thousands of genes that are present on each chromosome.

In many individuals with hypomelanosis of Ito, certain cells have the normal 46 chromosomes (one cell line) while others cells do not have the normal 46 chromosomes (second cell line). This second cell line may contain various abnormalities affecting the chromosomes such as a mutation in a specific gene, or the presence of an extra material on a chromosome (trisomy), loss of a portion of chromosome (monosomy), or a chromosomal translocation. Translocations occur when portions of certain chromosomes break off and are rearranged, resulting in shifting of genetic material and an altered set of chromosomes in the immediate daughter cells and their subsequent progeny cells. Specific chromosomal abnormalities have been identified in certain cases of hypomelanosis of Ito including ones affecting chromosome 9q33, chromosome 15q11-q13, chromosome Xp11 and Xp21.2. Chromosomal abnormalities have been identified in approximately 60 percent of cases of hypomelanosis of Ito and have included up to 64 distinct cytogenetic (chromosomal) abnormalities.

The chromosomal abnormalities affecting hypomelanosis of Ito occur after fertilization, often for unknown reasons (spontaneously). The disorder is not inherited. The specific gene(s) involved in the development of hypomelanosis of Ito have not been identified.



What are the treatments for ito hypomelanosis?

The treatment of hypomelanosis of Ito is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, dermatologists, neurologists, specialists who diagnose and treat skeletal disorders (orthopedists), dental specialists, specialists who diagnose and treat eye disorders (ophthalmologists), surgeons and other healthcare providers may need to systematically and comprehensively plan an affect child’s treatment.

The characteristic skin abnormality (hypopigmentation) of hypomelanosis of Ito tends to darken or fade without treatment. Some individuals may use cosmetics to hide or darken these areas. Antiseizure medications (anticonvulsants) may be used to treat infants and children with seizures, but are ineffective in some cases. Surgical techniques to treat seizures may be necessary for some affected individuals.

Additional treatment is symptomatic and supportive and consultation with proper specialists may be necessary. For example, consultation with an orthopedist may be necessary to treat scoliosis.

Services that may be beneficial to some children with hypomelanosis of Ito include special remedial education and other medical, social, and/or vocational services. Genetic counseling may be of benefit for affected individuals and their families.



What are the risk factors for ito hypomelanosis?

The precise cause for Ito hypomelanosis is unknown.

  • Genetic mosaicism and spontaneous gene mutations are linked to several occurrences.
  • The term "genetic mosaicism" refers to people who established two separate cell lines in their bodies as a result of a gene mutation that happened during embryonic development. •Chromosome discrepancies exist between the two cell lines (chromosomal mosaicism).
  • In many people with hypomelanosis of Ito, some cells (one cell line) contain the typical 46 chromosomes, whereas other cells do not (second cell line).
  • This second cell line may include chromosomal abnormalities, including chromosomal translocations, excess material on some chromosomes (trisomy), lack of some chromosomes (monosomy), and mutations in particular genes.
  • Translocations take place when pieces of specific chromosomes separate and are rearranged, changing genetic material and altering the set of chromosomes in the first daughter cells and the cells that follow.
  • About 60% of cases of hypomelanosis of Ito have chromosomal abnormalities, which can include up to 64 different cytogenetic (chromosomal) abnormalities.
  • After fertilization, the chromosomal defects that cause hypomelanosis of Ito frequently arise for unexplained reasons (spontaneously).
  • No one inherits the disease. It is unknown which specific gene or genes are responsible for the onset of hypomelanosis of Ito.


Symptoms
Crossed eyes (strabismus),Hearing problems,Increased body hair (hirsutism),Scoliosis,Seizures,Streaked, whorled or mottled patches of skin on the arms, legs, and middle of the body,Intellectual disability, including autism spectrum and learning disability,Mouth or tooth problems.
Conditions
Hypopigmentation,Psychomotor impairment
Drugs
Carbamazepine,Phenytoin,Antiseizure medications (anticonvulsants)



Is there a cure/medications for ito hypomelanosis?

Treatment for Ito hypomelanosis depends on the symptoms of each person.

  • The coordinated efforts of a group of professionals may be necessary throughout treatment.
  • A child's treatment may require the coordinated efforts of pediatricians, dermatologists, neurologists, dentists, specialists in the diagnosis and treatment of skeletal disorders (orthopedists), specialists in the diagnosis and treatment of eye disorders (ophthalmologists), surgeons, and other medical professionals.
  • Without therapy, the distinctive skin anomaly (hypopigmentation) of hypomelanosis of Ito has a tendency to darken or fade.
  • Some people could conceal or darken these spots with makeup.
  • Anticonvulsant drugs, which are used to treat seizures in newborns and children, can sometimes be ineffective.
  • For certainly affected people, surgical treatments to treat seizures may be required.
  • Additional symptomatic and supportive care may be required, as well as consultation with qualified specialists.
  • Some children with hypomelanosis of Ito may benefit from special remedial education as well as other medical, social, and/or occupational services.
  • Affected people and their families may benefit from genetic counseling.


Symptoms
Crossed eyes (strabismus),Hearing problems,Increased body hair (hirsutism),Scoliosis,Seizures,Streaked, whorled or mottled patches of skin on the arms, legs, and middle of the body,Intellectual disability, including autism spectrum and learning disability,Mouth or tooth problems.
Conditions
Hypopigmentation,Psychomotor impairment
Drugs
Carbamazepine,Phenytoin,Antiseizure medications (anticonvulsants)



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