TELEPHONITIS is a modern disease - and a consolation. When members of an affluent American family live streets apart in Los Angeles and as far away as New York, they are often connected only by their telephones, and this fragile coherence can be ruptured by neurotic whims, divorces and death.

Imaginary family unity is intermittently confirmed by the tenuous links of telephone calls; rejection and abandonment are signalled by the click of terminated conversation. Hanging up is a powerful metaphor for the times when an extended family, voluntarily or involuntarily, ceases to communicate.

Delia Ephron's parents, Henry and Phoebe Ephron, were Hollywood screenwriters whose films included Carousel and Funny Face. Delia's elder sister, Nora Ephron, wrote the scripts for Heartburn and When Harry Met Sally. Delia, too, is a screenwriter. She collaborated with her sister on films such as Sleepless in Seattle and Mixed Nuts, starring Steve Martin, which will be released this year.

Hanging Up is Delia's first novel. She says it is closely autobiographical, motivated by "the complicated and intense feeling" she had for her father, who was well known for his advanced case of telephonitis.

When he stopped calling her she knew he was dying. He died in 1992. No doubt, he would have been pleased to know that his tense relationship with Delia was to inspire a novel, which in turn was to inspire a film, to be directed by Nora. In a family like the Ephrons, no tragic or comic idea is wasted.

Conditioned by the cinema and television, today's readers have a limited attention span. Stories impeded by lengthy passages of description and analysis are impatiently thrown aside.

The stringent discipline of screenwriting has trained Delia Ephron to ensure that her readers' attention is never allowed to waver. Her prose is efficiently functional, dominated by dialogue that is so accurately colloquial that in your mind's ear you can hear it. Sister Nora could easily the film directly from the novel in its present form.

The principal character - the star - is at the centre of the novel, continuously on screen, as leading Hollywood actresses demand. Eve, the 44 year old narrator, is anxious about ageing, memory loss and a backside that is beginning to droop.

She tells with witty exasperation of the strain of being stuck with responsibility for the care of her 77 year old father, whom she simultaneously loves and hates.

Lou Marks, a senile, manic depressive alcoholic, who has always lived half his life "in the real world and half on the telephone", was once a successful screen writer. John Wayne, no less, gave him a souvenir bullet from his gun.

Lou has been divorced twice, secondly from a black nurse who got tired of giving him his tranquillisers. He now shuttles between the UCLA Geriatric/Psychiatric Hospital and the Jewish Home for the Aged in the San Fernando Valley, where nursing care costs $25 an hour.

Eve stays at home in Los Angeles, doing her best to control a difficult 16 year old son and his girlfriend and her cat, whose name is Buddha and who requires expensive veterinary attention. Eve has a part time occupation, organising parties for LA Events. Her current project is a big party for ear, nose and throat specialists at the Nixon Library.

Eve's husband is often away, interviewing odd people for public radio, and her two sisters are too busy to help. Gloria is a highpowered, egocentric New York magazine editor, who was the editor in chief of Harper's Bazaar until she was fired, and now edits, her own magazine, called Gloria. Maddy is a soap opera actress who resents the fact that her producer refuses to have her pregnancy written into the show.

Eve's mother left the family with her lover when she was 45. Eve recognises that her mother abandoned them because she realised that "life is finite". "Now my father has the dwindles," Eve tells herself. "It's late, but not too late, is it?"

Compared with her father, she is normal, but only compared with him. On one occasion, when she unplugs all the telephones and goes to bed alone in the quiet house, she thinks: "It's possible I'm relaxing. It's possible, but the feeling's not familiar so I can't be sure.

Many months must elapse before Hanging Up reaches a screen near you. In the meantime, I strongly recommend the book.