Trisomy 21 - Down Syndrome

When I started this series on the various trisomy genetic disorders, I knew this day would come. How does one even attempt to summarize Down Syndrome in a short blog post? I'll start with the disclaimer that none of my primers are intended to be all-inclusive. They're just a starting point to begin to familiarize the public at large with conditions that sometimes are quite rare and unknown. Down Syndrome doesn't really fit the unknown category, but it may fit the misunderstood category. People may think they know what Down Syndrome is, but have some serious misconceptions mixed in with their facts. My hope is this primer will make you want to learn more. Down Syndrome doesn't really fit the rare category either. Trisomy 21 is the most common single cause of birth defects, and occurs in approximately 5 of every 10,000 births. The condition is named for John Langdon Down, who described the condition in 1866. Dr. Jerome Lejeune linked Down Syndrome with an extra copy of Chromosome 21 in 1959.

Like all trisomy disorders, Down Syndrome occurs when there are three copies of one chromosome (Chromosome 21 in this case) or part of a chromosome. You can look at my general post on Trisomy to learn how this happens. It is an entirely random genetic mutation that cannot be prevented. Genetic counseling is advisable for people who have a family history of Down Syndrome, women above the age of 35, or parents who already have a child with Down Syndrome. Trisomy 21 can be diagnosed prenatally. Screening tests may indicate a higher risk for Down Syndrome and more conclusive diagnostic tests such as amniocentesis can confirm the diagnosis. These tests may carry risks of their own which should be considered carefully.

Each individual with Down Syndrome will be affected differently, but there are several common characteristics, including:

• decreased muscle tone
• single crease in palm of the hand
• cognitive delays
• impulsive behavior
• short attention span
• heart defects - atrial septal defect or ventricular septal defect
• eye problems - cataracts, corrective lenses
• gastrointestinal blockage - esophageal or duodenal atresia
• hearing problems
• narrow airway - sleep apnea

With improved medical treatment options, the average lifespan for individuals with Down Syndrome is nearly the same as normative peers. With early intervention and supportive family, individuals with Down Syndrome can graduate from high school, attend college, and maintain productive careers. Finally, I think I've shared this before, but I want to emphasize that each individual has something to contribute to society, and we have more in common than we may think. Please watch this short video by a young man with Down Syndrome and his parents. It is well worth your time.


Additional resources:

• PubMed Health - clinical description
• National Down Syndrome Society - especially this page
• National Down Syndrome Congress
• DownSyndrome.com
• Praying for Parker - especially this post

Trisomy 18

I'm continuing my series on Trisomy disorders. You can read the overview post here. Briefly, trisomy occurs when at conception an extra copy of one chromosome is transferred from the parents to their offspring. There are also forms of mosaic trisomy which occur during cell division, resulting in some cells having an extra chromosome and some not. Our chromosomes usually occur as pairs and are numbered from the largest chromosome (with the most genetic material) to the smallest, and Trisomy 18 refers to an extra copy of chromosome 18. Trisomy 18 has been in the news a bit more often recently because the former Republican Presidential Candidate Rick Santorum's daughter, Bella, has this disorder. She is three years old.

Trisomy 18 (also known as Edwards Syndrome) is the second most common form of trisomy, and occurs in 1 in every 3,000 live births. Because of the physical complications associated with Trisomy 18, many affected babies die before or shortly after birth.Affected males have a higher mortality rate than females. Most children (90%) die before the age of two months. However, some (mostly females) can live into their twenties and beyond, though they require assistance with daily living.

Trisomy 18 can be diagnosed prenatally. There are two levels of testing. The AFP or triple screen is a blood test that indicates statistical risk of Trisomy 18 (or other disorders) being present in a developing baby. This is not a specific diagnosis, but a "screening" test that may suggest further tests are advisable. Only about 11% of those with a "high risk" AFP result will go on to a confirmed diagnosis. Ultrasound is another method for screening. It may indicate physical differences in the baby, but the cause of those differences would be indeterminate. CVS (samples the structures that connect the pregnancy sac to the uterus) and amniocentesis (samples the amniotic fluid surrounding the developing baby) examine genetic material and give a more definitive diagnosis. There is a risk of miscarriage from these procedures. Following pre-natal diagnosis it's important to discuss the results with a genetic counselor who can explain what the results mean. I think it's also important to find resources and parents who have already lived with this disorder and know what you may be feeling and experiencing.

Each individual with Trisomy 18 may have a different combination of medical and developmental challenges. As with other forms of trisomy, in addition to the full Edwards Syndrome there is Partial Trisomy 18 (where only a portion of the chromosome has an extra copy) and Mosaic Trisomy 18 (where not all of the cells contain the extra copy) but these forms are less common, and each has similar potential challenges, including:

• Heart defects - a hole between the upper or lower chambers, or narrow aorta.
• Kidney problems
• A portion of the intestinal tract may be outside the stomach
• The esophagus may not connect to the stomach
• Clenched hands
• Pocket of fluid on the brain
• Rocker bottom feet
• Delayed growth
• Severe developmental delays
• Umbilical or inguinal hernia

Some of these medical challenges can be corrected with surgery, others may cause long-term issues such as congestive heart failure, and susceptibility to pneumonia.


For more information:
     Visit Susan's blog (buddzoo.com, where she shares her story of caring for her 3 year old daughter who has Trisomy 18. Susan also moderates a facebook group for families of Trisomy 18. (see comments below)
     Visit the Trisomy 18 Foundation here.
      Read stories from parents and family here.

Sunday Digest 43

Time to share the best of the things I've found while floating through cyber-space the last few weeks. I hope you'll visit and enjoy the links below and let them know you found them through The Simple Life:

1) One of my best new finds is Just a Lil Blog by Jim. It is great to get a dad's perspective on special needs parenting. His post People, Not Data really resonated with me and added to what was already brewing when I decided to write my own post "Making it Good" over at 5 Minutes for Special Needs.

2) Varda at The Squashed Bologna always has something to speak to me - several recent posts nailed me actually - but this one, which was a rerun from Hopeful Parents is one of my favorites. We need to start planning for the future of all of these young people now identified with autism or related disorders. The world is going to have to change big time!

3) I LOVED this take on Trisomy 21 by Tammy at Praying for Parker. So many of these "disorders" are naturally occurring conditions that, while challenging, have always been a part of the human condition.When will we accept this?

4) And, while we're on the subject of Down Syndrome, please listen to the testimony of this young man who reminds us that even though we're all different, we're all the same. We all need God. Hear how God used him to reach out to special needs children and their parents and teachers.

5) No matter what you're facing this week, it's good to remember that we each meet the future at the rate of 60 minutes per hour. Some things (the tedium of laundry and dishes) we wish could go by faster, but others, like the wonder of a child exploring the world around them we should stop and enjoy a little more. Tsh Oxenreider shared these thoughts at (In)Courage.

Trisomy 16

Trisomy 16 occurs when an individual has three copies of chromosome 16 instead of two copies (one from each parent.) For a brief layman's review of how trisomy occurs you can check out my overview post here.

Like other trisomies, there is full trisomy 16 and mosaic trisomy 16. In full trisomy 16 all of the body's cells have an extra copy of chromosome 16. This form is not compatible with life and causes miscarriage It is the most common chromosomal cause of miscarriage in the first trimester. In the mosaic form the effects are less severe and can vary widely. Symptoms of mosaic trisomy 16 include slow growth before birth (intrauterine growth retardation, IUGR), delayed development, heart defects, speech delays, kidney defects, and reproductive disorders. There is also a partial trisomy 16 (16p+ or 16q+) where there is an extra arm of chromosome 16. Interestingly, one source (NIH) I looked at indicated that one form of duplication (16p11.2+) may give rise to an autism spectrum disorder and language delay.

Trisomy 16 disorders can be discovered prenatally. I say discovered because often the tests cannot completely determine the level of trisomy 16 that is present. Alpha Fetal Protein (AFP) screening, chorionic villus sampling (CVS) and amniocentesis are all tests that can be performed, but each has its limitations and risks. It is important to discuss any test results with a genetic counselor. Amniocentesis is probably the most accurate diagnostic procedure. Ultrasounds can help determine whether or not any physical defects are present. Many of these can be corrected by surgery. It is sometimes possible that the trisomy is confined to placental tissues (which can lead to premature birth and/or hypertension in the mother). A pregnancy that continues beyond the first trimester would indicate mosaic trisomy at most.

I would strongly encourage you to read some stories from parents of children born with mosaic trisomy to learn more from their personal experiences. 

For more information please see the following links:

• Clinical summary
• PDF from Unique on Trisomy 16
• Overview from Disorders of Chromosome 16

Trisomy 13 - Patau Syndrome

I'm continuing my look at Trisomy disorders by profiling Patau Syndrome, Trisomy 13. Though discovered in 1657, the genetic cause was determined by Dr. Klaus Patau in 1960. As with all instances of trisomy, Patau Syndrome occurs when three copies of chromosome 13 are in some or all of an individual's cells. There are three forms of Trisomy 13:

1. Partial trisomy involves the presence of part of an extra copy of chromosome 13 in the cells.
2. Trisomy 13 mosaicism occurs when some of the cells have an extra chromosome 13.
3. Trisomy 13 has a full extra copy of chromosome 13 in all of the cells.

In some rare cases the extra genetic material may translocate and attach to a different chromosome. Trisomy 13 is fairly uncommon, occurring in approximately 1 in 10,000-21,700 newborns. Due to the severity of genetic damage (remember the lower the number of the chromosome the more genetic information it contains) the condition sometimes results in miscarriage or stillbirth (around 8% of prenatal diagnoses). Further, 80% of babies born with Trisomy 13 will not survive beyond their first year. However, those who do survive birth and early infancy can live to adulthood. Children with partial or mosaic Patau have an even more hopeful outlook. Therefore it saddens me to know that up to 64% of babies diagnosed prenatally with Trisomy 13 are eliminated by elective abortion.

Each child with Trisomy 13 will have different needs depending on what symptoms are evident. Some common issues include:

• Cleft lip or palate
• Close set eyes - may even fuse into one structure
• Extra fingers or toes
• Seizures
• Limb abnormalities
• Small head
• Small lower jaw
• Congenital heart defects - placement toward right side of chest, septal or ductal defects
• Holoprosencephaly - the forebrain doesn't divide properly

Often these physical challenges are detected first by ultrasound. MRI or CT scans may also be used. Chromosome studies are used to specify the type (Patau) and sub-type (partial, mosaic, or full) of Trisomy.

Caring for an infant with Trisomy 13 often involves addressing breathing issues like apnea, feeding problems, heart failure, seizures, and challenges with seeing and hearing. It is essential for families to find support as they walk through caring for a child with Trisomy 13. One well-known organization to contact is SOFT. Another is Hope for Trisomy 13 and 18.

How fitting that March is Trisomy Awareness month!

Sunday Digest 41

I think I'm slowly getting back into the swing of posting more frequently here (and keeping up at 5 Minutes, too...) Part of that is keeping up with following a lot of other blogs to keep the inspiration flowing. Here are some of the links I've come across in my perusing...

1) I wrote a post on Trisomy 9  about a month ago, and had the privilege of having a Trisomy 9 Mom stop by and comment on it. Turns out that Erin has her own blog where she writes about all the challenges they face. Here is a link to the story of her son's diagnosis, be sure to check out other posts, too.

2) OH...how I relate to Autism & Oughtisms post about the endless questions of childhood. Oh yes, we've been there, and still go there every once in a while. I've even blogged about it. "Why don't you crash into the car in front of you, Mommy?" was the child's favorite question for about three months and every time we were driving in the mini-van she would ask. Sadly we saw a bad car accident on the side of the road one day on the way home, and when I told her that's what happens when you crash, the question turned into "What happens to the car after it's crashed?" and I answered that one every time we saw a tow truck hauling a smashed up vehicle. Now I am asked to recall the finest details of my own childhood...and "I don't remember" is not a satisfactory answer. And yet, when I consider how hard she has worked to get her language to the level of asking questions...I swallow my impatience and try hard to answer in a way that will keep the conversation going.

3) Another been there, done that, moment from Bird on the Street - who has an older child with special needs, and twins (just like me)...but she's pregnant with baby number four, and we're not going there...hat's off to you, Katy! Anyway Katy tells the story of taking her three children to the pediatrician. Those of you without kids are thinking "What's hard about that?" and those with children are thinking "What was she thinking?" I actually do this all the time because I prefer the short term chaos to having three separate appointments where I have to find child care for one or two other children; but it ain't fun...let me tell you. Or let Katy tell you...

4) Had to check in with Praying for Parker. All of Tammy's posts teach me a lot. This one was especially touching to see Parker enjoying his favorite books with his Grandma and see the special bond they have. Sweet.

5) We are big Signing Time fans around here, although I need to expand our library of DVDs. We have used simple signs to help enforce rules, in particular, around our house. It helps me stay calm, for some reason, and it helps the kids pay a little extra attention. Rachel has been posting about a trip to Ghana where she helped a school for deaf children learn to use sign language in their curriculum. Reading these stories is a great reminder to count our blessings, and also to reach out to bless others...and also to keep exploring sign language with my kids.

That's it for this round...I hope you enjoy the links as much as I did. Please tell them you heard about them through The Simple Life.

Trisomy 9

Several months ago I started a series about Trisomy genetic disorders. I'm just getting back to that series after taking a brief break. You may want to refresh your memory on what Trisomy is and how it occurs. I've also written about Trisomy 8.

There are three forms of Trisomy 9:

1. Full Trisomy 9 is the most severe form in which every cell has three copies of chromosome 9. In most cases the developing embryo is not viable and the pregnancy will end in the first trimester by miscarriage. Some babies with full Trisomy 9 survive until birth, but only live for a short period of time.
2. Partial Trisomy 9 involves an extra portion of chromosome 9 is included in each cell. You can get an idea of what that might look like here (scroll down to diagnosis). Life expectancy with this form of Trisomy 9 varies widely. This form is generally more rare than full and mosaic forms.
3. Similar to Trisomy 8, Trisomy 9 often occurs in a mosaic form in which some, but not all, of an individual's cells have three copies of chromosome 9. Depending on the severity of medical challenges the life span of individuals with Mosaic Trisomy 9 can be shortened dramatically.

 Statistically, individuals with Trisomy 9 share several characteristics including medical issues, physical challenges, and behavioral traits. Each affected individual is unique and should not be "expected" to fit a certain developmental profile, but some common challenges include: low birth weight, congenital heart defects, global developmental delays, cognitive challenges, cranio-facial differences, and low muscle tone.
For more information on Trisomy 9, check out the following links:

• a fairly personal view from one family is here
• links to several other resources are here
• a more clinical view
• break out the tissue for this video about some girl scouts reaching out to one little girl with trisomy 9 mosaic syndrome.

Trisomy 8 - Warkany Syndrome

Trisomy 8 is a genetic disorder where three copies of chromosome 8 exist in every cell of an individual. You can review my earlier general trisomy post to refresh your memory on how that can occur. Recall that the chromosomes are numbered from largest (chromosome 1) to smallest. The larger a chromosome is, the more genetic information - instructions for cell development and function - it contains. Chromosome 8 is not the largest, but still contains a significant amount of DNA. Generally with three copies of chromosome 8 in each cell, too much damage is present for viability beyond early fetal development. Statistically Trisomy 8 is responsible for about 0.7% of miscarriages.

Some individuals have a different form of Trisomy 8 called mosaic syndrome, or T8mS. In T8mS only some of the person's cells have three copies of chromosome 8. The person may have cells in one type of tissue (e.g. blood or muscle) that have two copies of chromosome 8 and cells in another tissue (e.g. skin or eye) that have three copies. T8mS results from non-disjunction occurring during the process of mitosis (cell-division) rather than during meiosis (fertilization). Depending on when the mitosis goes awry there may be only a few effects, or several. However, the percentage of cells affected does not apparently correlate with the severity or which symptoms will appear.

Several distinct physical features are potential indicators of T8mS, including: low-set or abnormal ear shape, bulbed nose, strabismus (eye turns in), structural heart problems, palate abnormalities, and deep hand and feet creases. T8mS can also cause cognitive impairment and delays that may be mild or moderate. Treatment depends greatly on the symptoms of each individual. Heart problems can usually be corrected with surgery as can cleft palate. Strabismus can be treated with an eye-patch therapy or surgery.

More information on Trisomy 8 can be found here. During my research for this post, I also ran across the website for a support group called Unique. They distribute detailed information and provide support for individuals with T8mS and other genetic disorders.