DEAR DR. DONOHUE: We are friends with a lovely family that has eight children. Three of the girls and one of the boys were born with PKU. The others are free of the problem. What causes PKU, and why is protein not good for it? They are all healthy. The mother is expecting another child. What are the chances of PKU in this child? – A.R.

ANSWER: PKU – phenylketonuria – is a genetic condition in which the infant lacks an enzyme that rids the body of excess phenylalanine. Too much phenylalanine in the blood damages the brain. Phenylalanine is an amino acid, and amino acids are the fundamental units of protein. Many proteins contain this amino acid, and most people can use the amount needed for health and get rid of excess amounts of it. PKU babies cannot do so.

At birth these babies look normal. They might have fair skin and blond hair. If the condition is not detected early, the baby starts vomiting and can suffer from seizures. In time, without restriction of proteins containing phenylalanine, the brain is damaged and the infant has serious learning difficulties.

In many countries, testing all newborns for PKU is standard practice. Since that measure has begun, the number of PKU-damaged children has all but vanished in those countries.

Treatment for this condition is strict avoidance of all proteins that carry the phenylalanine amino acid. When that is done, children who lack the enzyme needed to metabolize that amino acid develop normally physically and in their ability to learn.

You might wonder why this disorder is called phenylketonuria, or PKU, when the source of trouble lies in phenylalanine. It’s because phenylketone is the byproduct of phenylalanine that is found in the urine.

The chances of this woman’s next baby being afflicted are one in four.

DEAR DR. DONOHUE: I am 80 years old and have seborrheic keratoses on my back. The dermatologist said I did not need to do anything about them. I went back six weeks later because they itched. He touched them with something. Can you tell me more about this? – E.L.

ANSWER: Few people pass through life without having one or more seborrheic keratoses. They are tan, brown or black blotches that range in size from .2 cm (0.08 inch) to 3 cm (1.2 inches) in diameter. Their surface can be smooth or rough, and most of the time they just sit there not causing any trouble. Only in a few people do they itch.

They can appear anywhere but most often are found on the chest, back, face or scalp. I opened my shirt just now to look at mine.

They aren’t cancer, and they don’t become cancer. What causes them is unknown.

Many people choose to leave them alone. If they itch or are a cosmetic problem, the doctor can freeze them with liquid nitrogen. I believe that’s what your doctor used when he touched you.

DEAR DR. DONOHUE: I have been using Pravachol for high cholesterol. I heard that it builds plaque in your arteries. Have you heard that? I am afraid to use it, but I haven’t stopped. Please advise. – J.B.

ANSWER: Where did you hear that? I have not heard it, and I don’t believe it.

Pravachol (pravastatin) is a cholesterol-lowering drug. In a head-to-head comparison with Lipitor, another similar cholesterol-lowering drug, it finished in second place. That’s not to say Pravachol is not a good and useful drug. In the study between the two medicines, the dose of Pravachol was smaller than its highest safe dose.

If your cholesterol is good, there’s no need for you to change. There is also no need for you to worry about plaque buildup in your arteries. Your medicine is lessening the chances for that to happen.

DEAR DR. DONOHUE: Is it true that chewing gum a lot will increase the size of the jaw? – E.C.

ANSWER: I don’t think so. If it were true, I should have the world’s largest jaw.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.

Copy the Story Link