Download Part Two - West Lakes GP Training

X-LINKED INHERITANCE WHERE THE MOTHER IS A CARRIER
Father
Parents
Mother
(Unaffected)
(Carrier)
Gametes
X
Y
X
X
At conception
Daughter
Daughter
(Carrier)
Son
Son
(Affected)
Fragile X Syndrome
Fragile X Syndrome is the most
common identifiable cause of
inherited intellectual
disability (mental handicap).
It can cause a wide range of
difficulties with learning,
as well as social, language,
attentional, emotional and
behavioural problems.
Supporting Genetics Education
for Health
www.geneticseducation.nhs.uk
Duchenne Muscular Dystrophy
(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.
Fig. 1.4 ©Scion Publishing Ltd
Histology photos courtesy of Dr Richard Charlton.
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 1
Single 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 Health
www.geneticseducation.nhs.uk
What Impact is Genetics
likely to make on the NHS in
the future?
Oncology
Especially using genetic
data to sub-type tumours –
informing treatment and
management
RED = overexpression of genes
ALL (acute
lymphoblastoid
leukemia) and AML
(acute myeloid
leukemia) cells look
alike, but microarrays
distinguish them
Supporting Genetics
Education for Health
www.geneticseducation.nhs.
Newborn Screening
Newborn
Bloodspot
Cards
Congenital hypothyroidism
Congenital hypothyroidism
PKU
PKU
MCADD
Cystic Fibrosis
Sickle Cell Disease & Beta
thalassaemia major
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
Robertsonian Translocation
21
14 14
14 14 21
21 21
21
14 14
21 21
Normal
14 14 21
Carrier
21
14 14 14 21
Trisomy 14
21
14 21 14 21
Trisomy 21
Cardiology
People with inherited risk
of cardiac problems
increasingly 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
Abacavir
• IMPACT – many thousands of
adverse drug reactions avoided
(5-10% had adverse reaction in
the past & response could be
fatal)
Please get in touch if you want further
information/support:
[email protected]
0191 241 8742
Institute of Genetic Medicine
Central Parkway
Newcastle Upon Tyne
NE1 3BZ
NGEDC website:
www.geneticseducation.nhs.uk
Thank you
Any Questions?