Trisomy 18 or Trisomy 18 or Edward's SyndromeEdward's Syndrome

By chahardolee, ehsan

DMD2-D

Trisomy 18 is a genetic disorder Trisomy 18 is a genetic disorder in which a person has a third copy in which a person has a third copy of material from of material from chromosome 18, 18, instead of the usual two copies.instead of the usual two copies.

Causes, incidence, and risk factorsCauses, incidence, and risk factors

Trisomy 18 is a somewhat common Trisomy 18 is a somewhat common syndrome. It is three times more common syndrome. It is three times more common in girls than boys. in girls than boys.

The syndrome occurs when there is extra The syndrome occurs when there is extra material from chromosome 18. The extra material from chromosome 18. The extra material affects normal development.material affects normal development.

SymptomsSymptoms

Clenched handsClenched hands

Crossed legs Crossed legs

Feet with a rounded bottom (rocker-bottom feet)Feet with a rounded bottom (rocker-bottom feet)

Low birth weight

Low-set earsLow-set ears

Mental delayMental delay

Poorly developed fingernailsPoorly developed fingernails

Small head (Small head (microcephaly))

Small jaw (Small jaw (micrognathia))

Undescended testicle

Unusual shaped chest (Unusual shaped chest (pectus carinatum))

Signs and testsSigns and tests

An exam during pregnancy may show an unusually large uterus and An exam during pregnancy may show an unusually large uterus and extra extra amniotic fluid. There may be an unusually small placenta . There may be an unusually small placenta when the baby is born.when the baby is born.

A physical exam of the infant may show unusual fingerprint patterns. A physical exam of the infant may show unusual fingerprint patterns. X-rays may show a short breast bone. X-rays may show a short breast bone. Chromosome studies will will show trisomy 18, partial trisomy, or show trisomy 18, partial trisomy, or translocation..

Other signs include:Other signs include:

Hole, split, or cleft in the iris of the eye (Hole, split, or cleft in the iris of the eye (coloboma))

Separation between the left and right side of the abdominal muscle (Separation between the left and right side of the abdominal muscle (diastasis recti))

Umbilical hernia or or inguinal hernia

There are often signs of There are often signs of congenital heart disease, such , such as:as:

Atrial septal defect (ASD) (ASD)

Patent ductus arteriosus (PDA)Patent ductus arteriosus (PDA)

Ventricular septal defect (VSD)Ventricular septal defect (VSD)

Tests may also show kidney problems, including:Tests may also show kidney problems, including:

Horseshoe kidneyHorseshoe kidney

HydronephrosisHydronephrosis

Polycystic kidneyPolycystic kidney

TreatmentTreatment

Treatment of children with trisomy 18 is Treatment of children with trisomy 18 is planned on a case-by-case basis. Which planned on a case-by-case basis. Which treatments are used depend on the treatments are used depend on the patient's individual condition.patient's individual condition.

PreventionPrevention

Tests can be done during pregnancy Tests can be done during pregnancy to find out if the child has this syndrome.to find out if the child has this syndrome.

Genetic testing is recommended for Genetic testing is recommended for parents who have a child with this parents who have a child with this syndrome and who want to have more syndrome and who want to have more children.children.