MovieChat Forums > Lorenzo's Oil (1993) Discussion > A question about the cured boys

A question about the cured boys

posted 17 years ago by jwalla76
5 replies | jump to latest

I have a question about the happy active boys who were shown at the very end of the movie. These boys still have the defective gene, but because they took the oil, the disease is controlled and is no longer progressing.

I am wondering if these boys, who are now adults having children of their own, can spread the disease to their own sons, or make their own daughters into carriers. This is a new situation, as children with this disease did not survive to adulthood in the past.

[–] Doctor_Strangelove24 17 years ago

They can transmit a carrier state to their daughters, but not sons.

The type of ALD that Lorenzo had is X-linked recessive.

[–] cosmic_quest 17 years ago

As the other poster said, it's not possible for a child of an ALD sufferer to pass the full blown disease onto their children and only their daughters can become carriers. As a point of interest, a few years ago, there was a documentary in the UK about ALD boys in their late teens who were tired of taking the oil and the very rigid diet they had to follow and wanted to see if they could come off it as it had been hypothesised that between the ages of five and ten were when the ALD gene was active. It would be interesting to see the results of what happened to those boys.

"I always pretend to root for Gryffindors but, secretly, I love my Slytherin boys."~ Karen, W&G

[–] jwalla76 17 years ago

I thought that when a genetic disease was recessive, both parents had to carry the gene for the child to get sick. Certainly that's true of cystic fibrosis. When one parent carries the gene and the other does not, a child may be a carrier, but none of their children will actually get the disease.

Since men have one X chromosome, I wonder what would happen if a boy like Lorenzo married a woman who happens to be a carrier, on one of her Xs, and the child happened to inherit the bad chromosome from both parents. The child would obviously be a girl because she didn't inherit a Y chromosome, but she would be a girl with 2 ALD X chromosomes. Or would she? The survival into adulthood of these people will raise some interesting questions.

Your point about the gene possibly becoming inactive is very interesting. Maybe boys will outgrow the disease when they can survive, and no further problems will arise in the future as the disease becomes completely curable.

[–] cosmic_quest 17 years ago

CF is an autosomal genetic illness, which means the condition results in damage/deletion to one of the first 22 chromosomes of the human karyotype. ALD is a sex-linked genetic condition so it is carried through a the sex-chromosomes (the X or Y chromosome). In ALD, it is carried through the X chromosome so if a girl of a carrier mother receives the damaged X chromosome then she would be a possible carrier but the undamaged X chromosome from her father would compensate leaving her unafflicted by the condition. However, a boy would have the illness because they only have the one X chromosome (the damaged one) with nothing to compensate. Haemophilia and Muscular Dystrophy are two other sex-linked genetic conditions.

Your theory of a girl inheriting two damaged X chromosomes (from her carrier mother and her father who has the actual condition but took the Oil) is very interesting. Technically, it should never happen because a father who knows he has the condition would ensure he had genetic counselling before having a child to ensure his wife is not a carrier. However, accidents happen! What would the result be? Very likely, the baby girl would die in the womb because having two damaged X chromosomes might not be viable for life.

"I always pretend to root for Gryffindors but, secretly, I love my Slytherin boys."~ Karen, W&G

[–] 17 years ago

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