Healthy babies for disease carriers

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Healthy babies for disease carriers

A Jerusalem woman suffering from myotonic dystrophy is due to give birth in

December to a healthy baby identified as a normal ovum and two-day-old

embryo by a unique but complicated polar body pre-gestational diagnosis

(PGD) that weeded out those with the disease...

Myotonic dystrophy, which occurs in one in 10,000 infants, statistically

could be handed down to half of her offspring. She herself suffers from a

mild form of the disease, which can cause serious muscle weakness, mental

retardation, hair loss, and cataracts in the most severe cases.

Although known genetic diseases in newly created embryos can be identified

by removing one cell from an eight-cell blastomere mechanically or by using

lasers, the error rate can be relatively high and damage could be done to

the embryo. But testing polar bodies, which are microscopic and unnecessary

cells on the unfertilized and fertilized egg that will in any case

degenerate, has been found to be much more accurate. It can mean not having

a baby with Tay-Sachs disease, who will inevitably die after great suffering

­ and not aborting; instead, one can have a completely healthy child. ...

Women with fertility and genetic problems who are longing to have a baby

undergo tremendous emotional stress. And if they finally manage to produce a

healthy embryo that is implanted and give birth to what is supposedly a

healthy baby but turns out to have the disease, they suffer an emotional

blow beyond description, " ...

The technique can be used to detect any genetic mutation, either a disease

caused by one molecularly analyzable gene or several, " said Dr. Ephrat

Levy-Lahad, head of the medical genetics unit. Among these are Tay-Sachs and

familial dysautonomia, which occur mostly in Jews, as well as thalassemia,

myotonic dystrophy, neurofibromatosis, fragile X, hemophilia, and Marfan's

syndrome, which affect every population. " We are prepared to set up our lab

for any genetic disease people come with, caused not only by dominant genes

with a 50% chance of each embryo being affected but also recessive genes,

with one in four having the disease and two being carriers.

" We select healthy eggs in a very labor-intensive procedure, then fertilize

it with the husband's sperm to produce embryos, and then perform a second

polar-body examination to make sure that the blastomere is healthy. We

believe that polar-body biopsy is the best, because you don't know the

long-term effects of removing a cell from the embryo, and the less

manipulation, the better. Most labs that do ordinary PGD use lasers for a

biopsy, but we use only mechanical means, because we worry about any damage

the heat could cause, " ...