It's been a rough end to what started out as a record-breaking season for openly gay characters on the small screen.

After a 2012-13 season that featured a record number of lesbian, gay, bisexual and transgender characters on TV, this past week's wave of cancellations may drastically alter those statistics.

Gone are shows that featured prominent gay story lines including NBC's The New Normal and CBS' Partners. Both were semi-autobiographical series about the lives of its nearly all openly gay creators -- Ryan Murphy and Ali Adler on the former, David Kohan (who's not) and Max Mutchnik for the latter -- and featured two happy, committed gay couples. Worth noting, half of both couples were played by openly gay actors -- New Normal's Andrew Rannells (opposite Justin Bartha) and Partners' Michael Urie (opposite Brandon Routh).

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A November Hollywood Reporter survey found that gay characters on TV -- including couples on the recently renewed Modern Family and Grey's Anatomy -- were helping drive voters to a historically unprecedented support of gay marriage.

"This data would suggest that seeing this stuff makes it more socially acceptable," THR pollster Jon Penns aid at the time. "Views on gay marriage have exponentially gone in its favor since 2002."

The THR poll came a month after watchdog group Gay & Lesbian Alliance Against Defamation released its annual "Where We are on TV" report that found a record number regular LGBT characters on the small screen.

"The sheer number of characters who will no longer be on the air means diversity on television is once again at risk," GLAAD national spokesman Wilson Cruz tells The Hollywood Reporter. "Following a season with the highest recorded number of LGBT characters, these cancellations mean networks have to make a concerted effort to ensure the 2013-2014 season truly reflects the diversity of their audience. With inclusive programs like Modern Family and Glee continuing to lead the ratings and collect praise from critics, it's in a network's best interest."

While shows including NBC's Go On, Don't Trust the B---- in Apt. 23 (created by the openly gay Nahnatchka Khan), Malibu Country, 90210, Emily Owens, M.D., The Office andL.A. Complex all featured leading gay characters, the expected loss of Smash also stands out as it featured at least four regulars including co-star Christian Borle's Tom.

Also gone are broader favorites including TNT's Southland and Happy Endings, whose Max Blum (Adam Pally) was dubbed by critics including the A.V. Club as "TV's least stereotypical gay character."

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Fox's Glee might also see one of its young bisexual characters exit as co-star Heather Morris (Brittany) doesn't have a deal to return for season five of the Fox musical.

And while The New Normal may be gone from NBC after just one season, the network has already given the green light to Sean Saves the World, starring Sean Hayes (Will & Grace) as an openly gay single father.

Also untold are just how many of the more than 40 new shows ordered to series in the past week also include LGBT characters -- as well as how many could change as many of the comedies and dramas continue to refine story lines as the networks search for their next breakouts. (NBC's Go On, after it was ordered to series last year, wound up writing Julie White's Anne as a lesbian seeking group therapy following the death of her partner.)

Meanwhile, TV's returning shows with LGBT characters also are telling new story lines -- including coming out in the 1980s on The Carrie Diaries and adultery in a lesbian relationship on ABC's Grey's Anatomy. The Shonda Rhimes medical drama starring Sara Ramirez (Callie) and Jessica Capshaw (Arizona) is a a four-time GLAAD Awards nominee for outstanding drama, taking home the prize in 2012 after featuring a lesbian wedding.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit