Transcript Diagnosis PPT 1

Using Anatomy and Physiology
• Patient has symptoms and signs.
• Doctor tests for specific diseases, and hits
the books!
–Or, Actually… The Web…
• Online Mendelian Inheritance in Man –
database that collects information on
diseases and disorders.
• Can be searched for symptoms and signs
to help diagnosis problems.
• Using the OMIM search we can find genetic
causes and gene malfunctions.
• Often specific genes can influence many
systems… and we need to know how to help
the patient.
• Has an unusual set
of medical problems.
–Premature
–Has a large head
(macrocephaly)
–Seizures
–Abnormal eye
alignment
(stabismus)
–Atrial Septal defect
–Mom had
polyhdroamniosis
during pregnancy …
• As our young
patient grows up we
notice…
–Limited social
contact
–Enlarged cerebral
ventricles
–Increased urine
output, but low level
of salts
–Calcium within the
kidneys
(nephrocalcinosis)
• Does not fit “neatly” into our normal
diagnosis.
• Time for research.
• Step one: OMIM
–http://www.ncbi.nlm.nih.gov/sites/entrez?db=om
im
• Step two: search his symptoms…
• How many results did we get?
• If we change our symptoms do our results
change?
• How can we be sure of our diagnosis?
The fewer search results the better, but only
one or two is very limiting and can lead you
the wrong way.
• SEARCH: macrocephaly AND
polyhydramnios AND seizures
• Results: 8
• Options:
–POLYHYDRAMNIOS, MEGALENCEPHALY,
AND SYMPTOMATIC EPILEPSY
–D-BIFUNCTIONAL PROTEIN DEFICIENCY
–CARDIOFACIOCUTANEOUS SYNDROME
–OSTEOPATHIA STRIATA WITH CRANIAL
SCLEROSIS
–COSTELLO SYNDROME
• Many of our possible search results can
give us a variety of symptoms, some our
patient has and some he does not.
• Now what?
• Look at others with the same symptoms…
do they have anything in common?
• Our patient and several other children have
the same symptoms.
• They do not live close enough to have a
common environmental cause to the
disease.
• They all have unaffected siblings…
So Doc, NOW WHAT?
• But for what? We know they have the same
symptoms…
• For any type of genetic similarities NOT
common to the rest of the population…
• We look at a Microarray!
• This cool bio tool looks for areas of
homozygosity (both alleles the same) in a
person who has the disease, that is NOT
present in those who do not…