It could have been a lot worse.

That's a generous assessment of the overall performance of the nation's mutual funds in 1990, a year wracked by economic uncertainty and worrisome world events."The year turned out to be the best possible one we could have expected, with the average mutual fund down only 6.27 percent in a very difficult investment environment," said A. Michael Lipper, president of Lipper Analytical Services, which tracks the nation's mutual funds. "It was, however, the first time since 1975 that we experienced an industrywide performance decline that was more than just a single percentage point or so."

Although international and gold-oriented funds disappointed, there were successes in 1990. Funds investing in health-related stocks and foreign currencies excelled.

"The products of biotechnology companies are moving from the laboratory to the marketplace and generating strong sales for these companies after years of losses," explained Michael Gordon, portfolio manager for Fidelity Select Biotechnology, which led the nation's mutual funds with a 44.38 percent gain in 1990. "This trend should only accelerate in 1991, which bodes well for investment in biotech firms."

Most responsible for the success of the fund was Amgen, which rose 150 percent. The second-largest holding, Genentech Inc., rose 45 percent, while third-largest Immunex Corp. was up 90 percent. The fund continues to add to those three holdings.

"Health care stocks have done well because health care spending continues to grow as a percentage of our gross national product," said Andrew Offit, portfolio manager for Fidelity Select Health Care, up 24.28 percent to place fifth among all funds. "The watchword for the coming year is not so much what the economy does, as what the government does in terms of regulation of products."

Among that fund's holdings, in pharmaceuticals Bristol-Myers Squibb rose 25 percent; in medical technology U.S. Surgical gained 132 percent; and in health services Medical Care International increased 87 percent.

Results of the foreign currency funds were also impressive.

"Over the course of 1990, the U.S. dollar dropped dramatically relative to the European currencies and we were able to benefit from that performance," said Judy Pagliuca, portfolio manager for Fidelity Sterling Performance Portfolio L.P., up 36.43 percent to notch second place for the year. "Because we're an indexed fund, we should continue to trade with the value of the U.S. dollar on foreign exchange markets in 1991."

Around 20 percent of the performance of such funds has come directly from currency appreciation, pointed out Mark Fox, portfolio manager for the Shearson Lehman Brothers Pound Sterling Performance Portfolio L.P., which is up 35.33 percent.

"Regarding 1991, I suspect that the dollar will continue to depreciate against most major currencies," said Fox. "However, I believe that the deutsche mark and the yen will likely perform better than the pound sterling."

Top-performing mutual funds of 1990, according to Lipper, were:

Fidelity Select Biotechnology, Boston, $222 million assets, 2 percent "load" (initial sales charge), $1,000 minimum investment, up 44.38 percent.

Fidelity Sterling Performance Portfolio L.P., $3.3 million assets, 0.40 percent "load," $5,000 minimum, up 36.43 percent.

Shearson Lehman Brothers Global Currency Funds: Pound Sterling Performance Portfolio L.P., New York, no-load, $1,000 minimum, up 35.33 percent.

Financial Strategic Portfolio - Health Sciences, Denver, $158 million assets, $250 minimum, up 25.79 percent.

Fidelity Select Health Care, $366 million assets, 2 percent load, $1,000 minimum, up 24.28 LECKEYContinued from DX

percent.

Kemper Global Income Fund, Chicago, $44 million assets, 4.5 percent load, $1,000 minimum, up 22.66 percent.

Shearson Lehman Brothers Global Currency Funds: Deutsche Mark Performance Portfolio L.P., $6 million assets, no-load, $1,000 minimum, up 21.67 percent.

Fidelity Deutsche Mark Performance Portfolio L.P., $12 million assets, 0.40 percent load, $5,000 minimum, up 21.21 percent.

Scudder International Fund, Boston, $196 million assets, no-load, $1,000 minimum, up 21.08 percent.

Phoenix Multi Portfolio Capital Appreciation Fund, Greenfield, Mass., $18 million assets, $500 minimum, up 20.47 percent.