(From Dr. Coutinho, 4 Oct 2000, by Brian Buschman)
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Marfan syndrome is a genetic problem with the formation of fibrillin from a gene on chromosome 15. It leads to:
1) Arachnodactitily
2) Pidgin chest
3) Mitral valve prolapse
Both EDS and osteogenesis imperfecta are collagen synthesis problems. Osteogenesis imperfecta has brittle bones and a blue sclera.
EDS is caused by problems with lysyl hydroxylase related to copper. Without lysyl working properly you do not get proper cross linking of collagen.
An enzyme for neural lipids causes motor problems and blindness. In addition to the blindness patients have a red spot on their retina.
Accumulation of sphingomyelin and cholesterol leads to neural problems. As with any accumulation of lipids you will see foamy cells.
Gaucher’s disease involves splenomegaly and is related to Gaucher’s cells which are PAS positive and filled with lipids.
MPS are also called either Hurler’s disease or Hunter’s disease and involve accumulation of mucopolysaccharides causing retardation and retinal clouding.
VonGeirke’s disease is a G6P deficiency.
Muscle phosphate deficiency. Muscles lack sufficient ATP therefore cause cramps and stuff.
Pompe’s disease is associated with acid maltase deficiency which leaves glycogen all over the body.
Homogentisic oxidase blocks metabolism of phenylalanine. The patients are seen with black urine and black deposits around the body.
PKU is a deficiency of phenylalanine hydroxylase that causes retardation with deposits of phenylalanine. Patients look pale because phenylalanine is not able to be converted into melanin.
Family hypercholestyramia has a messed up gene coding for the LDL receptor. It leads to very high blood cholesterol levels and causes premature arteriosclerosis. Homozygosity is bad and rare. Heterozygosity is not as bad but is more common.
Neurofibromatosis type 1 and 2 are both diseases related to tumor suppressor genes that have gone bad. Often there are sub-q nodules which are neurofibulary tangles.
CF is from a mutation of the CFTR gene. CF causes problems with transmembrane ion movement.
DMD has a pseudohypertrophy of the calves and replacement of muscle with fibrotic tissues. It causes very high CKMM levels.
Myotonia has involuntary muscle contractions. If you shake their hand they will be unable to let go. A state of “muscle tonicity.”
Polycystic kidney disease is one of the diseases with the highest rates of penetrance. It is nearly 100% and shows up late in life. Because of these two situations it is common and the gene is usually passed on (since patients do not die from it until after they have kids). These patients will suffer acute and chronic renal failure.
Downs babies present with a:
1) Flat face and occiput.
2) A brush field spot on the eyes resembling a scrap.
3) Simmeon’s crease which is a single horizontal crease across their hands.
These babies have:
1) Cleft-lip and palate.
2) Microophthalmia
3) Polydactility (what do you think that you could do with an extra finger?)
In Edwards you will see:
1) Rocker bottom feet.
2) Clinched fists with overlapping fingers (the outer fingers are a little sideways)
3) CNS malformation that can include meningoencephalocele.
This is that guy with the cat like cry because of a problem with the short arm of chromosome 5 (5q-)
They have atrophic testes making them sterile. With the bad testis it causes them to have a lack of many of their secondary sex characteristics.
These ladies again are sterile because they have streak ovaries. They also show short stature with a webbed neck and broad chest (their nipples are more lateral then they should be).
Fragile X is a Xp- that only causes a problem in males. In women they have the other “good” X to take care of it. In guys you see long faces, large ears and large testis. If you see the buzzword “large testis” think Fragile-X.
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