daughter son parents gametes at conception x-linked inheritance where the mother is a carrier...
TRANSCRIPT
Daughter Daughter Son Son
Parents
Gametes
At conception
X-LINKED INHERITANCE WHERE THE MOTHER IS A CARRIERFather Mother
X Y XX
(Carrier) (Affected)
(Carrier)(Unaffected)
Fragile X Syndrome
Supporting Genetics Education for Health
www.geneticseducation.nhs.uk
Fragile X Syndrome is the most common identifiable cause of inherited intellectualdisability (mental handicap). It can cause a wide range of difficulties with learning,as well as social, language, attentional, emotional and behavioural problems.
Duchenne Muscular Dystrophy
Fig. 1.4 ©Scion Publishing Ltd
Histology photos courtesy of Dr Richard Charlton.
(a) Affected boys stand up by bracing their arms against their legs (Gower’s manoeuvre) because their proximal (eg muscles are weak. (b) and (c) Muscle histology (Gomori trichrome stain). Normal muscle (b) shows a regular architecture of cells with dystrophin (brown stain) on all the outer membranes. (c) Shows muscle from a 10-year-old affected boy. Note the disorganisation, invasion by fibrous tissue and complete absence of dystrophin. Histology photos courtesy of Dr Richard Charlton, Newcastle upon Tyne.
Ethical Issues 1
Mr P was recently diagnosed with ADPKD. Having realised each of his children has a 50% chance of having inherited the condition from him, Mr P asks the GP to organise a kidney ultrasound for his two children aged 10 and 7, to see if they have inherited the condition. The GP should do so.
Consider the statement above to what extent do you agree or disagree with it?
Ethical Issues 2• Duchenne Muscular Dystrophy (DMD) is a progressive
neuromuscular disorder affecting ~ 1 in 3000 male births.• Boys with DMD are diagnosed between 4-5 years In
about 2/3 cases, the mother is a carrier. • No treatment
Neonatal screening of all male births should be performed to identify affected boys so their mothers can be tested to see if they are carriers and so at risk of having further affected pregnancies
Making a referral
• Draw a family pedigree• Patient’s date of birth, address, telephone
number, GP, NHS Number• Affected / carrier person’s name, Date of Birth,
genetic condition, relationship to patient• Details of anyone already known to genetics
Taking a sample
• Ensure the patient is aware of the possible implications of the result for themselves and other family members before the blood sample is taken.
• Obtain consent for the procedure, document whether
the patient is happy for results to be shared with other relevant health professionals and family members.
• Arrange how, when and from whom the patient will
receive the results.
Sending a blood sample to Genetics 1Single gene disorder• 5ml venous blood sample in an EDTA tube • Clearly label blood tubes with 3 reference points,
name, date of birth and NHS number
• On a form need the same details +– details of the test required– details of affected/carrier family members– Clearly mark as Urgent with weeks gestation– Telephone contact of person giving result
Sending a blood sample to Genetics 2
• For Autosomal Recessive conditions such as Cystic Fibrosis, Tay Sachs, send a sample from both partners
• Send each partner on a separate form with linking identifiers
Sending a blood sample to Genetics 3
Chromosome Disorders: • 5ml venous blood sample in a Lithium
Heparin tube • Details as before
Genetics in Primary Care Module
GPS_06_001 Why does genetics matter in primary care practice?
GPS_06_003 Interpreting family histories: Autosomal conditions
GPS_06_004 Interpreting Family Histories and Identifying Patients Part 2: Sexlinked Conditions and Conditions with Variable Patterns of Inheritance
GPS_06_006 Talking genetics: Communicating genetic information
Supporting Genetics Education for Health
www.geneticseducation.nhs.uk
Resources• Familial Hypercholesterolaemia scenarios • Collecting, Recording and Interpreting Family
History Information • 'Taking a Family History' Videos • PowerPoint files of clinical photographs • PowerPoint files on specific genetic conditions • PowerPoint files explaining core genetic
concepts • The Genomic Basis of Therapeutics series • Dietetics "Genetics and Obesity"
Supporting Genetics Education for Health
www.geneticseducation.nhs.uk
Supporting Genetics Education for Healthwww.geneticseducation.nhs.uk
What Impact is Genetics likely to make on the NHS in
the future?
Supporting Genetics Education for Health
www.geneticseducation.nhs.uk
ALL (acute lymphoblastoidleukemia) and AML (acute myeloid leukemia) cells look alike, but microarrays distinguish them
Oncology
RED = over-expression of genes
Especially using genetic data to sub-type tumours – informing treatment and management
Congenital hypothyroidism
PKU
Newborn BloodspotCards
Congenital hypothyroidism
PKU
MCADD
Cystic Fibrosis
Sickle Cell Disease & Beta thalassaemia major
Newborn Screening
Down’s Syndrome Screening
Combined Test 11 – 14+2 weeks:- Nuchal Translucency - Serum PAPPA and Free βhCG
Serum Screening 15 – 20 weeks: - AFP, βhCG, Oestriol, Inhibin A
The future – Free cell fetal DNA
Down’s Syndrome
• 95% Regular Trisomy• 4% Translocation • 1% Mosaic
1414 21 21
1414 21 21 14 2114
21
1414 2114
21
2114
21
14 21
211414
21
14
Normal Carrier Trisomy 14 Trisomy 21
Robertsonian Translocation
CardiologyPeople with inherited risk of cardiac problemsincreasingly identified
Screening & treatment Available - saving lives
Pharmacogenomics Genetic information can identify the right treatment for
a patient
e.g. Abacavir (used to treat HIV & AIDS)• Gene test now used routinely
in UK to identify people who might be hypersensitive
• IMPACT – many thousands of adverse drug reactions avoided (5-10% had adverse reaction in the past & response could be fatal)
Abacavir
Please get in touch if you want further information/support:
[email protected] 241 8742
Institute of Genetic MedicineCentral Parkway
Newcastle Upon TyneNE1 3BZ
NGEDC website:www.geneticseducation.nhs.uk
Thank you
Any Questions?