10代の喫煙男性に精子の遺伝子の突然変異を認めた　

1998/10/2ロイター　米国国立研究所の研究によると、喫煙する若い男性の精子は遺伝子の異常を伴った形の異常な精子が増えていることを発見した。これは、喫煙男性が不妊症になりやすいというだけでなく、遺伝的に異常な子供を産む可能性も増加するとしている。

Sperm mutations found in teen smokers
NEW YORK, Oct 02 (Reuters) -- Young men who smoke may be both compromising their fertility and increasing their risk of fathering a child with genetic abnormalities, according to the results of study published in the October issue of Fertility and Sterility.

The researchers, led by Dr. Andrew J. Wyrobek of Lawrence Livermore National Laboratory in Livermore, California, found a significantly increased proportion of abnormally shaped sperm and sperm with genetic defects in the semen of smokers compared with nonsmokers.

They estimate that these abnormalities could double the risk of fathering a child with an aneuploidy syndrome -- ``one of the most serious and common chromosomal abnormalities affecting (humans)''. This would lead to an excess of 1,000 cases of aneuploid children born in the US each year attributable to smoking fathers alone. Aneuploidy is also linked to increasing paternal age, and to treatment with certain cancer drugs.

The study included 25 healthy, 18-year-old men in the Czech Republic. Ten of the young men said they smoked a pack of cigarettes per day for at least 2 years, while the other 15 men did not smoke.

The findings also indicate, the authors say, that young men who smoke may be less fertile than nonsmoking men.

In their report, the researchers stress that cigarette smoking is generally part of an overall lifestyle that includes alcohol consumption, stress, and other factors that could have negative effects on male fertility. Therefore, the findings ''could be due to lifestyle characteristics and not smoking alone,'' they say.

Wyrobek and his team conclude that cigarette smoking among teenage men has adverse effects on sperm quality that ``may affect male fertility and may increase future chances of fathering offspring with aneuploidy syndromes.''

``It remains to be shown whether smoking (and drinking) cessation may reduce the frequency of aneuploid sperm to levels found in nonsmokers,'' they write.

Dr. Alan DeCherney, editor of the journal, comments in a press release that ``the adverse health effects of these activities have been well documented, but these studies showed the adverse effects on fertility and the health of future generations.''

SOURCE: Fertility and Sterility 1998;70:715-723.