Term
| Antenatal (prenatal) screening |
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Definition
| identifies the risk of a disorder so that further tests and a prenatal diagnosis can be offered. |
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Term
| Examples of Antenatal screening include: |
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Definition
| Untrasound imaging, biochemical testing, diagnostic testing, amnioscentesis, chorionic villus sampling and rhesus antibody testing. |
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Term
| Ultrasound Imaging is carried out at 8-14 wks to produce |
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Definition
| a dating scan – used to determine the stage of pregnancy and calculate a due date |
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Term
| Ultrasound imaging is carried out at 18-20 wks to produce |
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Definition
| an Anomaly Scan, which shows up the any serious physical abnormalities in the foetus |
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Term
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Definition
| monitor physiological changes that occur during pregnancy eg. Concentrations of human chorionic gonadotrophin |
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Term
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Definition
| A definitive test that produces definite results about whether or not a person is suffering from a specific condition |
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Term
| Amnioscentesis and Chorionic Villus Sampling |
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Definition
| Used to prepare a person’s karyotype which shows their complete chromosome complement |
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Term
| Amnioscentesis involves obtaining |
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Definition
| amniotic fluid containing foetal cells. The cells are then used to create a karyotype, allowing detection of abnormalities |
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Term
| Chorionic villus sampling (CVS) involves obtaining |
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Definition
| a sample of placental cells. The cells are then used to create a karyotype, allowing detection of chromosome abnormalities |
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Term
| Amnioscentesis is carried out |
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Definition
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Term
| Chorionic villus sampling (CVS) is carried out |
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Definition
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Term
| Disadvantage of chorionic villus sampling |
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Definition
| It causes higher incidence of miscarriage than amniocentesis |
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Term
| Pregnant women who are rhesus negative |
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Definition
| will have immune system problems if her baby is Rhesus positive as the fetus red blood cells are seen as “foreign” |
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Term
| All newborn babies are screened for PKU (phenylketonuria) |
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Definition
| By having their blood tested of presence of excess phenylalanine. |
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Term
| Pedigree charts can be used to |
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Definition
| analyse patterns of inheritance in genetic screening and counselling |
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Term
| An example of autosomal recessive inheritance is |
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Definition
| Cystic Fibrosis (cc=disease) |
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Term
| Autosomal recessive inheritance |
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Definition
| Trait is expressed relatively rarely, skips generations and sufferers are homozygous recessive. |
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Term
| Autosomal dominant inheritance |
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Definition
| Trait is expressed every generation, each sufferer has an affected parent and sufferers are homozygous dominant or heterozygous eg Hh or HH=disease |
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Term
| An example of autosomal dominant inheritance |
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Definition
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Term
| An example of autosomal incomplete dominance |
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Definition
| Sickle cell disease SS=sufferer HS=partial |
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Term
| In sex-linked recessive traits |
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Definition
| More males are affected than females, none of the sons of an affected male show the trait and all sufferers are homozygous recessive. sufferer=XhY male, XhXh female |
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Term
| An example of a sex linked recessive trait |
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Definition
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