Trisomy Disorders

Posts Tagged ‘trisomy 13

Clinical ocular manifestation of Patau’s syndrom (trisomy 13)–own observations

2011

Kanigowska KGrałek MSeroczyńska M.

Source

Z Kliniki Okulistyki Instytutu “Pomnik – Centrum Zdrowia Dziecka” w Warszawie. kkan@wp.pl

Abstract

PURPOSE:

The purpose of the article is to present the clinical abnormalities of Patau’s syndrome (trisomy13).

MATERIAL AND METHODS:

Examination was performed on 18 months old girl with trisomy13 in which we noted characteristic malformations in ocular system. The patient underwent cataract surgery and intraocular lens implantation in right eye. In this case the diagnosis of trisomy 13 was confirmed by karyotype.

RESULTS:

Inferonasal iris colobomas, anterior-posterior form of persistent hyperplastic primary vitreus (PHPV), persistent tunica vasculosa lentis (PTVL), coloboma of the lens and cataract in right eye were found. Cataract surgery was performed with good results. Systemic abnormalities included heart defect, brain defect, cleft palate, small head, dysplastic ears, mental retardation, epilepsy and increased muscle tone.

CONCLUSIONS:

The child with the presence of inferonosal iris colobomas and cataract and with other systemic and dysmorfic findings, should have kariotype examination to look for trisomy 13.

PubMed

Illustrations Polydactyly - an infant's hand Polydactyly – an infant’s hand Syndactyly Syndactyly

Alternative names    Return to top

Patau syndrome

Definition    Return to top

Trisomy 13 is a syndrome associated with the presence of a third (extra) number 13 chromosome.

Causes, incidence, and risk factors    Return to top

Trisomy 13 occurs in about 1 out of every 5,000 live births. It is a syndrome with multiple abnormalities, many of which are not compatible with life. More than 80% of children with trisomy 13 die in the first month.

Trisomy 13 is associated with multiple abnormalities, including defects of the brain that lead to seizures, apnea, deafness, and eye abnormalities.

The eyes are small with defects in the iris (coloboma ). Most infants have a cleft lip and cleft palate, and low-set ears. Congenital heart disease is present in approximately 80% of affected infants. Hernias and genital abnormalities are common.

Symptoms    Return to top

Signs and tests    Return to top

The infant may have a single umbilical artery at birth. There are often signs of congenital heart disease:

Gastrointestinal x-rays or ultrasound may reveal abnormal rotation of the internal organs.

MRI or CT scans of the head may reveal a structural abnormality of the brain, called holoprosencephaly, where the 2 cerebral hemispheres are fused.

Chromosome studies show trisomy 13, partial trisomy, trisomy 13 mosaic, or translocation.

Treatment    Return to top

Because of the severity of congenital defects, life-sustaining procedures are generally not attempted.

Support Groups    Return to top

 

Support Organization for Trisomy 18, 13 and Related Disorders (SOFT) — www.trisomy.org

 

Expectations (prognosis)    Return to top Extremely short survival time is expected. Rarely, affected persons survive to adulthood.

Complications    Return to top

Complications begin almost immediately. They include breathing difficulty or lack of breathing (apnea), deafness, vision problems, feeding problems, seizures, heart failure, and others.

Calling your health care provider    Return to top

Call for an appointment with your health care provider if you have had a child with Trisomy 13, and you plan to have another child.

Prevention    Return to top

Trisomy 13 can be diagnosed prenatally by amniocentesis with chromosome studies of the amniotic cells. Trisomy 13 mosaicism and partial trisomy 13 also occur. Parents of infants with trisomy 13 caused by a translocation should have genetic testing and counseling, which may help them prevent recurrence.

 

Update Date: 4/20/2005

Medline Plus

……………..

Trisomy 13 Facts

Trisomy 13 syndrome is a disorder of human chromosomes which occurs in approximately 1 in 10,000 live born infants. Trisomy 13 is due to the presence of an extra #13 chromosome. Approximately 80% of infants with Trisomy 13 syndrome will have a full trisomy while the remainder will have a trisomy due to a rearrangement called a translocation or have mosaicism (two different cell lines).

Infants born with Trisomy 13 have a recognizable pattern of physical features that often allow the health professional to make the diagnosis of the syndrome. Notable physical birth defects and sometimes, anatomic changes of internal organs are present. Findings of significance include small head size (microcephaly); small eyes (microphthalmia) or sometimes absent eye or faulty development of the retina. Cleft lip or cleft palate or both occur in about 60% of children. In addition, there are a number of less medically significant physical findings that are helpful in diagnosis. These include variations of ear shape, changes on the palm of the hand, and extra fingers and toes. Changes in foot development, including changes to the heel, the so-called rocker bottom foot, can occur.

Heart Defects

About 80% of children with Trisomy 13 will have a congenital heart defect. These can include: ventricular septal defect – an opening between the lower chambers of the heart which prevents the heart from pumping blood correctly (a heart murmur is generally heard from this finding); atrial septal defect – an opening between the two upper chambers of the heart making it difficult for the heart to pump sufficient oxygen rich blood to body tissues (a heart murmur is often heard); patent ductus arteriosis – a defect involving the lack of closure of the channel that usually closes near the time of birth; dextrocardia – location of the heart on the right side of the chest; on occasion more medically serious heart defects can occur in Trisomy 13.

Synonyms:       Trisomy 13

                        Patau Syndrome

                        Trisomy 13-15

D Trisomy Syndrome

 (these last two terms are usually not used at the present time)

Medical Problems

 The major implications of Trisomy 13 involve a predisposition to congenital malformations (birth defects) mentioned above, an increased mortality in infancy, and a developmental disability in older children. In addition, older infants can have visual difficulties because of the findings mentioned above and a hearing loss. The increased mortality is related to difficulties with breathing due to either interrupted breathing (apnea), or problems of lung development. In addition, gastroesophageal reflux and feeding problems can occur and predispose to aspiration adding to this risk. Usually the heart defects are not serious enough to be a major health threat in the newborn period.

Important and Common Birth Defects in Trisomy 13

Omphalocele Holoprosencephaly 60% (an anatomic defect of the brain involving failure of the forebrain to divide properly)

Kidney Defects 30%Skin defects of the scalp 20%

Common Disorders in infants and young children with Trisomy 13

feeding difficulties

gastroesophageal reflux

slow post natal growth

apnea seizures

hypertension

kidney defects

developmental disabilities

scoliosis

Routine Follow-up care of infants with Trimsomy 13

Routine child care/anticipatory guidance

Cardiac evaluation

Eye evaluation

Hearing test Referral for Infant pre-school/early childhood intervention program

Referral for Infant pre-school/early intervention program

Ongoing support

Scoliosis check through childhood

Routine immunizations for immunization including chicken pox 

Trisomy.org

……………

Trisomy 13 Mosaicism

Welcome to Trisomy Disorders!!!!!!!!!!

This blog replaces our previous one on AOL Hometown when Hometown closed down on October 31st.

What are Trisomy Disorders?

Genes are the blueprint for our bodies. Almost every cell in the body has a copy of the blueprint, stored inside a sac called the nucleus. Genes are beaded along chromosomes, which are tightly bundled strands of the chemical substance deoxyribonucleic acid (DNA). Humans usually have 23 pairs of chromosomes, with two sex chromosomes that decide gender and 44 chromosomes that dictate other factors, such as growth and function. A chromosome disorder is caused by an alteration in the number or genetic structure of chromosomes. Trisomy (‘three bodies’) means the affected person has 47 chromosomes instead of 46. Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy. Children affected by trisomy usually have a range of birth defects, including delayed development and intellectual disabilities.

Risk factors
The addition of an extra chromosome usually occurs spontaneously during conception. The cause of this is unknown and prevention is not possible. Some of the risk factors may include:

  • Maternal age – women over 37 years of age are more likely to have babies with chromosomal disorders than younger women.
  • Paternal age – some research tentatively suggests that older men (over 50 years of age) are more likely to father babies with chromosomal disorders than younger men.
  • Number of children – studies indicate that women who have given birth to four babies have a slightly increased risk of their fifth or subsequent babies having a chromosomal disorder.

Down syndrome

The incidence of Down syndrome in Victoria is around one in every 481 births. Down syndrome is also known as Trisomy 21, because the person has three copies of chromosome 21 instead of two. There are three types of Down syndrome. The most common is Standard Trisomy 21, in which the father’s sperm or the mother’s egg cell contains the extra chromosome. In Mosaic Down syndrome, the extra chromosome spontaneously appears as the embryo develops. Translocation Down syndrome, which accounts for approximately five per cent of cases, is inheritable. Some of the characteristics of Down syndrome may include:

  • Outwardly slanted eyes
  • Exaggerated fold of skin on the inside of the eye
  • Flat ears set low on the head
  • Flattened face
  • Small teeth
  • Relatively short arms and legs.

Edward syndrome

The incidence of Edward syndrome in Victoria is around one in every 1,613 births. Edward syndrome is also known as Trisomy 18, because the person has three copies of chromosome 18 instead of two. Some of the characteristics of Edward syndrome may include:

  • Defects of the kidneys, ureters, heart, lungs and diaphragm.
  • Cleft lip or cleft palate.
  • Small skull (microcephaly).
  • Malformations of the hands and feet – including missing thumbs, club feet and webbing between the fingers and toes (syndactyly).
  • Neural tube defect, where the spinal cord, meninges and blood vessels protrude through a gap in the vertebrae (myelomeningocele).
  • Malformations of the sex organs.

Down syndrome

The incidence of Down syndrome in Victoria is around one in every 481 births. Down syndrome is also known as Trisomy 21, because the person has three copies of chromosome 21 instead of two. There are three types of Down syndrome. The most common is Standard Trisomy 21, in which the father’s sperm or the mother’s egg cell contains the extra chromosome. In Mosaic Down syndrome, the extra chromosome spontaneously appears as the embryo develops. Translocation Down syndrome, which accounts for approximately five per cent of cases, is inheritable. Some of the characteristics of Down syndrome may include:

  • Outwardly slanted eyes
  • Exaggerated fold of skin on the inside of the eye
  • Flat ears set low on the head
  • Flattened face
  • Small teeth
  • Relatively short arms and legs.

Edward syndrome

The incidence of Edward syndrome in Victoria is around one in every 1,613 births. Edward syndrome is also known as Trisomy 18, because the person has three copies of chromosome 18 instead of two. Some of the characteristics of Edward syndrome may include:

  • Defects of the kidneys, ureters, heart, lungs and diaphragm.
  • Cleft lip or cleft palate.
  • Small skull (microcephaly).
  • Malformations of the hands and feet – including missing thumbs, club feet and webbing between the fingers and toes (syndactyly).
  • Neural tube defect, where the spinal cord, meninges and blood vessels protrude through a gap in the vertebrae (myelomeningocele).
  • Malformations of the sex organs.

Patau syndrome

The incidence of Patau syndrome in Victoria is around one in every 4,000 births. Patau syndrome is also known as Trisomy 13, because the person has three copies of chromosome 13 instead of two. Some of the characteristics of Patau syndrome may include:

  • Small skull (microcephaly).
  • An abnormal opening in the skull.
  • Malformations of part of the brain.
  • Structural defects of the eyes.
  • Cleft lip or cleft palate.
  • Additional toes or fingers (polydactyly).
  • Congenital heart disorders, such as ventricular septal defect.
  • Neural tube defect, where the spinal cord, meninges and blood vessels protrude through a gap in the vertebrae (myelomeningocele).
  • Malformations of the sex organs.

Signs during pregnancy

Sometimes, signs of trisomy disorders may be evident during the pregnancy. Some of these signs may include:

  • Too much amniotic fluid surrounding the baby (polyhydramnios).
  • Only one umbilical cord artery.
  • A smaller than expected placenta.
  • The baby is small for its gestational date.
  • The baby is less active than expected.
  • Congenital defects, including cleft palate or heart abnormalities, are picked up during ultrasound scans.

Diagnosis methods

Prenatal tests that can help detect trisomy disorders include:

  • Ultrasound scans – sound waves are used to create a picture.
  • Maternal serum screening – a specialised blood test.
  • Amniocentesis – a sample of the amniotic fluid is taken and examined.
  • Chorionic villi sampling – a sample of cells from the chorion, the tissue that will ultimately become the placenta, is taken and examined.

Where to get help

  • Your doctor
  • Paediatrician
  • Genetic Health Services Victoria Tel. (03) 8341 6201
  • SOFT. Australia – Support Organisation for Trisomy Tel. (02) 9521 6039

Things to remember

  • Humans have 23 pairs of chromosomes.
  • A trisomy is a chromosomal disorder characterised by an additional chromosome, so the person has 47 instead of 46.
  • Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy.

We will be a clearinghouse for information on all the Trisomy conditions.

Pat O’Connor

October 30, 2008


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