Tag Archives: heart Defects

Cat Eye Syndrome / Schmid Fraccaro Syndrome

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Cat Eye Syndrome is the more common name for a condition involving a partial trisomy or tetrasomy of part of chromosome 22. A small extra chromosome (humans normally have only 2) made up of the top half of chromosome 22 – the “p” arm, as well as the portion of the long arm of chromosome 22 down to the breakpoint q11.2, is found to be present either three times (trisomy) or four times (tetrasomy ).

Cat Eye Syndrome is also known in the literature as Schmid-Fraccaro Syndrome, Partial Tetrasomy 22, or Inv Dup(22)(q11) (Inverted Duplication).     It is often referred to as Cat Eye Syndrome as some of the people affected may have coloboma of the iris – which make their eyes appear to look like cat’s eyes. This feature however, is only reported in about half of the known cases. The earliest reports stem back over 100 years ago, but the first association

Clinically, this is one of the more variable syndromes. People who have Cat Eye Syndrome can be anywhere from normal to suffering from severe malformations. This has proven true of the people who have joined our group, who have this condition.

Some of the features seen in people with CES include coloboma of the iris, anal atresia, ear tags and/or ear pits, heart defects, and kidney malformations, but because of the variability, there have been reports of malformations affecting almost every organ.

Cognitively, people with CES can be considered either normal intelligence, or have varying degrees of mental delay, although it is rare to see severe mental impairment in this condition.

The condition usually arises spontaneously, but our group does have some members who have CES and have passed it on to their children.

Trisomy 18/Edwards syndrome

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Trisomy 18, also known as Edwards syndrome, is a condition which is caused by a error in cell division, known as meiotic disjunction.  Trisomy 18 occurs in about 1 out of every 2500 pregnancies in the United States, about 1 in 6000 live births.  The numbers of total births increase significantly when stillbirths are factored in that occur in the 2nd and 3rd trimesters of pregnancy.

Unlike Down syndrome, which also is caused by a chromosomal defect, the developmental issues caused by Trisomy 18 are associated with medical complications that are more potentially life-threatening in the early months and years of life. 50% of babies who are carried to term will be stillborn, with baby boys having higher stillbirth rate than baby girls.

At birth, intensive care admissions in Neonatal units are most common for infants with Trisomy 18. Again, baby boys will experience higher mortality rates in this neonatal period than baby girls, although those with higher birth weights do better across all categories.

Some children will be able to be discharged from the hospital with home nursing support for their families. And although less than 10 percent survive to their first birthdays, some children with Trisomy 18 can enjoy many years of life with their families, reaching milestones and being involved with their community.  A small number of adults (usually girls) with Trisomy 18 have and are living into their twenties and thirties, although with significant developmental delays that do not allow them to live independantly without assisted caregiving.

What causes Trisomy 18?
At conception, 23 chromosomes from the father and 23 chromosomes from the mother combine to create a baby with a set of 46 chromosomes in each cell. A trisomy occurs when a baby has three #18 chromosomes instead of the normal two. This is something that happens at conception. And although many parents worry about this, it is important to know that parents have done nothing before or during pregnancy to cause this disorder in their child.

Are there different types of Trisomy conditions?
The most common trisomy is Trisomy 21, also known as Down syndrome, where a baby has three of the twenty-first chromosome. Trisomy 18 is the second most common trisomy and occurs when a baby has three of the eighteenth chromosome. This results in 47 chromosomes instead of the normal 46 in the affected cells. It is this extra genetic material that causes the problems associated with Trisomy 18. The third most common is Trisomy 13, also known as Patau syndrome.

While there are different types of Trisomy 18, this does not mean one is better for a child than another.  With each type, there is a range of possibilities. Some children are medically fragile while others thrive; some children walk while others are confined to wheelchairs. It is hard to say how the extra chromosome will impact an individual child from the genetic diagnosis alone.

Types of Trisomy 18:

  • Full Trisomy 18: The most common type of Trisomy 18 (occurring in about 95% of all cases) is full Trisomy. With full Trisomy, the extra chromosome occurs in every cell in the baby’s body. This type of trisomy is not hereditary. It is not due to anything the parents did or did not do—either before or during pregnancy.
  • Partial Trisomy 18: Partial trisomies are very rare.  They occur when only part of an extra chromosome is present. Some partial Trisomy 18 syndromes may be caused by hereditary factors. Very rarely, a piece of chromosome 18 becomes attached to another chromosome before or after conception. Affected people have two copies of chromosome 18, plus a “partial” piece of extra material from chromosome 18.
  • Mosaic Trisomy 18: Mosaic trisomy is also very rare. It occurs when the extra chromosome is present in some (but not all) of the cells of the body.  Like full Trisomy 18, mosaic Trisomy is not inherited and is a random occurrence that takes place during cell division.

What are the characteristics of Trisomy 18?
The genetic material from the extra eighteenth chromosome can cause a variety of problems with varying severity. Just as children with Down syndrome can range from mildly to severely affected, the same is true for children with Trisomy 18. This means that there is no hard and fast rule about what Trisomy 18 will mean for your child. However, statistics show that there is a high mortality rate for children with Trisomy 18 before or shortly after birth.

Typical characteristics of Trisomy 18 include:

  • Heart defects:
    • VSD (Ventricular Septal Defect): a hole between the lower chambers
    • ASD (Atrial Septal Defect): a hole between the upper chambers
    • Coarctation of the aorta: a narrowing of the exit vessel from the heart
  • Kidney problems
  • Part of the intestinal tract is outside the stomach (omphalocele)
  • The esophagus doesn’t connect to the stomach (esophageal artesia)
  • Excess amniotic fluid (polyhydramnios)
  • Clenched hands
  • Pocket of fluid on the brain (choroid plexus cysts)
  • Rocker bottom feet
  • Delayed growth
  • Small jaw (mycrognathia)
  • Small head (microcephaly)
  • Low-set ears
  • Strawberry-shaped head
  • Severe developmental delays
  • Umbilical or inguinal hernia

Trisomy 13 syndrome

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Trisomy 13 syndrome is a disorder of human chromosomes which occurs in approximately 1 in 10,000 live born infants. Trisomy refers to three copies of a chromosome instead of the normal two and in Trisomy 13 there is the presence of an extra #13 chromosome. Approximately 80% of infants with Trisomy 13 syndrome will have a full trisomy (affecting all cells) while the remainder will have a trisomy due to a rearrangement of cells called a translocation (an attachment of all or part of one chromosome to another chromosome) or have mosaicism (two different cell lines in an individual such as normal cells and trisomy cells).

Infants born with Trisomy 13 have a recognizable pattern of physical features that often allows the health professional to make the diagnosis of the syndrome. (Genetic testing must be done to confirm diagnosis.) 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 an 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. This can include: ventricular septal defect (VSD), 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 (ASD), 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 (PDA), a defect involving the lack of closure of the channel that usually closes near the time of birth and thus remains open; and dextrocardia, which is a location of the heart on the right side of the chest. The majority of heart lesions are usually not those that cause death in the neo-natal period but on occasion more medically serious heart defects can occur in Trisomy 13.

Synonyms:

  • Trisomy 13
  • Patau Syndrome
  • Trisomy 13-15
  • D Trisomy Syndrome

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

Medical Problems
The major implications of Trisomy 13 involve a predisposition to the congenital malformations (birth defects) mentioned above, an increased mortality in infancy and developmental and motor 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 either to interrupted breathing (apnea) or problems of lung development. In addition, gastroesophageal reflux (backward flow of a small amount of stomach contents upward to the throat) and feeding problems can occur and predispose to aspiration (small amount of liquid inhaled or trickled into the lungs) which can precipitate aspirational pneumonia. 

Important and Common Birth Defects in Trisomy 13

  • Omphalocele 10%
  • 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 Trisomy 13

  • Routine child care/anticipatory guidance
  • Cardiac evaluation
  • Eye evaluation
  • Hearing test
  • Referral for Infant pre-school/early intervention program
  • Ongoing Support
  • Scoliosis check through childhood
  • Routine immunization including chicken pox