Kathleen Winter and Emma Donoghue among novelists who will compete for £30,000 prize in strong year for female writers
A former Sesame Street writer's first novel, which tells the story of a child born as a hermaphrodite in the far north-east corner of Canada, will compete for this year's Orange prize for fiction.
Kathleen Winter, for the book Annabel, was one of three debut novelists named on the shortlist for the £30,000 prize for female authors – a sign of "the rude health of women's writing," according to Bettany Hughes, chair of the judging panel.
Also striking are the big, difficult subjects the six books tackle, including abuse in a care home, civil war, and almost unimaginable torture in Emma Donoghue's Room, a book last year shortlisted for the Man Booker prize.
Hughes, a historian and broadcaster, said the subjects were undoubtedly serious but all six were "written with such a lightness of touch" to make them extremely readable.
She added: "All of them really deal with immensely serious and in some ways quite dark subjects, but the luminosity of the writing makes them more than bearable. It makes them essential, riveting and charismatic books."
The other debut novelists on the list are the former teacher Emma Henderson for Grace Williams Says it Loud and Serbian-American Téa Obreht for The Tiger's Wife. Obreht recently featured as the youngest member of New Yorker magazine's "20 under 40" club of writers it considers the most talented of their generation.
Donoghue's story of a mother and son imprisoned for years in a single room, resonant of the Josef Fritzl case, is the best-known book on the list.
The list is completed by Aminatta Forna's The Memory of Love, set in the aftermath of the civil war in Sierra Leone, and US writer Nicole Krauss's Great House.
Judges took six hours to whittle the list down from 20 to six and were, by the end, unanimous in their choice, said Hughes.
As chair, Hughes had the gruelling – but joyous, she insisted – task of reading all 130 books up for the prize, often lugging around four at a time and squeezing 10 hours of reading time into a day. "I only sleep for four or five hours," she said. "The revelation for me was just how much reading anybody can pack in to a day."
Hughes read hard copies of all the books because she said it was too easy to skim read on a Kindle.
The most surprising omission from the shortlist is arguably Jennifer Egan's multi-layered A Visit From the Goon Squad, which has done fantastically well in US literary prizes, beating Jonathan Franzen to the fiction prize from the National Books Critics Circle.
Hughes said all 20 longlisted books had been extraordinary in their own way. "When it came down to it we found the six we chose were all immensely readable and somehow important."
Just getting shortlisted will mean a healthy spike in sales for the books, but the writers have to wait until 8 June before the £30,000 winner is named at a ceremony at London's Royal Festival Hall.
Whoever wins follows in the impressive footsteps of writers including Barbara Kingsolver, who won last year for The Lacuna; Marilynne Robinson for Home in 2009; Zadie Smith for On Beauty in 2006 and Andrea Levy for Small Island in 2004.
The prize was created in 1996 to celebrate and promote fiction written by women. The judges this year include the publisher Liz Calder, the novelist Tracy Chevalier, the actor Helen Lederer and the BBC broadcaster Susanna Reid.
Hughes said the calibre of submissions had been markedly high. "Our judging meeting fizzed for many hours with conversations about the originality, excellence and readability of the books in front of us," she said.
The contenders
Room by Emma Donoghue
Shortlisted for last year's Man Booker prize, Room is the best-known novel on the list, gripping and moving readers with the story of five-year-old Jack, imprisoned in a room, 11ft by 11ft, with his mother.
The Memory of Love by Aminatta Forna
Forna, born in Scotland to a Sierra Leonean father and Scottish mother, sets her second novel in the aftermath of the Sierra Leone civil war examining how people survive the memory of such brutal experiences. The Guardian's reviewer called it "a remarkable novel: well researched, well thought out, well written."
Grace Williams Says It Loud by Emma Henderson
This debut novel tells the story of Grace, sent to the Briar mental institute aged 11, who falls in love with Daniel, an epileptic who can type with his feet. It is a novel that lifts spirits and, despite its setting and depiction of terrible abuse, is often "side-splittingly" funny, say judges.
Great House by Nicole Krauss
One half of one of the most formidable literary couples in the US – her husband is Jonathan Safran Foer – Krauss's third novel tells connected stories exploring loss and memory. At its centre is a desk with 19 drawers, which has importance to four different characters.
The Tiger's Wife, by Téa Obreht
The youngest writer on the list – just 25 – Obreht was born in Belgrade before her family left when she was seven, as war broke out. Big things are predicted for this New York-based writer and this book, her first novel, is partly set in the aftermath of the war in Serbia.
Annabel by Kathleen Winter
Winter's family moved from Gateshead to Newfoundland when she was very young. Her first novel tells the story of a baby born with male and female genitalia who is brought up as a boy in the hyper-male hunting culture of Labrador.