NIPT Screening Flashcards
where is down syndrome most prevalent?
It is more prevalent in babies of women greater than 40 years or very young women.
what are the three types of down’s syndrome called?
- trisomy 21 - translocation - mosaic
what is trisomy 21?
- Most common type of down syndrome
- People with trisomy 21 have a whole extra 21 chromosome in every well of their body, so they have 47 chromosomes instead of 46.
- Mild - moderate learning disabilities and may have more associate health conditions.
- This is a random event which is not influenced by any parental action.
what is down’s syndrome translocation?
- This Down’s syndrome is due to an extra part which is translocated or joined to another chromosome in the cell.
- 1/3 babies, this extra chromosome by inherited from one of the parents. Parental age is not a factor.
- They do not differ from those with trisomy 21.
- They have 46 chromosomes however one chromosome is large becasye it carried the extra 21.
what is mosaic down’s syndrome?
- This type of Down’s syndrome occurs when an extra chromosome 21 appears in only some of the cells.
- Depending on the proportion of cells affected, the degree to which the person is affected may sometimes but not always, be lessened.
what are the associated health conditions with down’s syndrome?
- Cardiac (congenital heart disease)
- Low muscle tone
- Digestion/gut
- Hearing and vision
- Thyroid (hypothyroidism)
- Recurrent cough and infections
- Weight issues
- More likely to have autism spectrum disorder (ASD)
- More likely to have Attention deficit hyperactivity disorder (ADHD)
More likely to have Dementia from an early age
what are the physical characteristics of down’s syndrome?
- Up-slanting palpebral fissures
- Epicanthic folds
- Brachycephaly
- Flat occiput
- Protruding tongue
- Hypotonia
- Board hands
- Palm of hand with only one crease
what is up slanting palpebral fissures?
Up-slanting palpebral fissures - open of the eyelids slanting down
what is the epicanthic folds?
skin fold of the upper eye covering the corner of the eye
what is brachycephaly?
the back of the head becomes flattened, causing the head to widen, and occasionally the forehead bulges out.
what is protruding tongue?
large in portion to other structures of the mouth
what is hypotonia?
decreased muscle tone
what does it mean for living with down’s syndrome?
- Immediate response to the idea of having a baby with down’s - health conditions can be treated and managed as they would for any child.
- Preferred language - think carefully and avoid using negative assumptions as in I’m sorry etc
- Living with down’s syndrome - they have a lot of potential. They can live healthy and fulfilling lives as part of their families community.
what is edward’s syndrome?
- A life limiting condition, 7 in 10 pregnancies diagnosed with this syndrome will end at 12 weeks in miscarriage. Although chance in miscarriage or still birth with decrease with gestation.
what are the three types of edward’s syndrome?
- Three types of Edward’s syndrome - trisomy 18 - translocation - mosaic
what is trisomy 18?
- Most common
- Other forms of Edward’s will have less effect upon baby but can by identified by screening
- It is 3 copies of chromosome 18. this extra chromosome in cells severely disrupts normal development.
- This usually happens during the formation of either the egg or sperm.
- Babies born with T18, around 5 in 10 will live longer than on week. And around 1 in 10 live longer than 5 years.
what is translocation? edwards syndrome
- Sometimes the extra number 18 chromosome, or part of it, is attached to another chromosome in the egg or sperm.
- There may be a rearrangement of part or all of one chromosome, called translocation.
The child be less affected in these cases. - Babies who do not have full form of the condition (translocation or mosaic forms) may have longer life expectancy and need less medical attention.
- There may be a rearrangement of part or all of one chromosome, called translocation.
is trisomy 18 inherited translocation?
- This is the only form of T18 that may be inherited by a parent. As some parents may have balanced translocation, meaning the 18 chromosome is attached to another chromosome but this isn’t affecting their health.
what is mosaic? edwards syndrome
- Can be less severe form of Edward’s syndrome, as only some of the cells have the extra copy of chromosome 18.
- How affected depends on the number and type of cells that have the extra chromosome.
- Some babies may only be mildly affected other may be severely.
Babies who do not have full form of the condition (translocation or mosaic forms) may have longer life expectancy and need less medical attention.
what are the characteristics of edwards syndrome?
- They are extremely likely to have a wide range of health issues involving nearly every organ system.
- 9 in 10 babies will have heart issues.
- Most babies will have difficulties with breathing (apnoea) and feeding issues.
- Around half will have hearing loss and issues with their muscles and joints
- More likely to get infections and require on going medical care.
- Life-limiting, around 13% chance of living past first birthday. If they survive to one, there is a 80% chance of living to 5 and beyond.
- Rare chance of living to adulthood.
Their development will be slower and require ongoing assistance.
what are the physical characteristics of edwards syndrome?
- Low set and malformed ears
- Small mouth and jaw
- Prominent occiput
- Ptosis - drooping of the upper eyelid
- Wide epicanthic folds
- Clenched hand and overlapping fingers
what is ptosis?
drooping of the upper eyelid
what is patau’s syndrome?
- Life limiting conditions and miscarriage or still births are common in these pregnancies.
what are the three types of patau’s syndrome?
- trisomy 13, translocation, mosaic
what is trisomy 13?
- Most cases result from having 3 copies of chromosome 14 in each sell instead of the usual 2.
- The extra genetic material disrupts of course of development, causing the characteristics of trisomy 13.
- 4 in 10 will live longer than 6 months
- 1 in 10 will live longer than 5 years
what is translocation? patau’s syndrome?
- T13 can also occur when part of chromosome 13 becomes attached (translocated) to another chromosome during the formation of reproductive cells or very early in fetal development.
- Translocated T13 have 2 normal copies of chromosome 13, plus an extra copy of chromosome 13 attached to another chromosome.
- In rare cases only part of chromosome 13 is present in 3 copies.
- The physical signs and symptoms in these cases may be different than those found in full T13.
is translocation for patau’s syndrome inherited?
- This is the only form of T13 which may be inherited from parents. As some parents may have balanced translocation, meaning the 13 chromosome is attached to another chromosome but this isn’t affecting their health.
what is mosaic? patau’s syndrome
- Small percentage of people with T13 have an extra copy of chromosome 13 in some cells.
- This condition is called mosaic T13.
- The severity depends on the type and number of cells with the extra chromosomes.
- The physical features are often milder than those with full T13.
- Babies who do not have full form of the condition (partial or mosaic forms) may have longer life expectancy.
what are the characteristics of patau’s syndrome?
- 11% chance of living past first birthday.
- If they live longer than a year, 9% chance of living to 5 and beyond.
- This includes those who have mosaicism or partial trisomy.
- May be born with wide range of health conditions, some of which may be serious.
- Will need care and support throughout life.
- Will have delayed development, forebrain defects, intellectual disabilities and structural anomalies.
- 8 in 10 babies will have heart issues
- 6 in 10 will have brain abnormalities
- 5 in 10 will have serious problems with their eyes
- They also may need medical assistance breathing and eating
what are the cardiac and central nervous system defects involved with patau’s syndrome?
- Holoprosencephaly
- Ventriculomegaly
- microcephaly
- Posterior fossa and malformations
- Postaxial polydactyly
- Echogenic kidneys
- Ventriculomegaly
what is holoprosencephaly?
a condition that occurs in the first two or three weeks of pregnancy and results in abnormal development of the brain
what is ventriculomegaly?
a condition in which the ventricles appear larger than normal on a prenatal ultrasound.
what is microcephaly?
small head
what is posterior fossa and malformations?
special group of central nervous system anomalies that present during infancy with hypotonia, developmental delay, microcephaly, or hydrocephalus.
what is postaxial polydactyly?
an extra digit or a part of digit on the ulnar or fibular side of hand or foot.