Pop star Justin Bieber treated an ailing youngster to the night of her life by inviting the fan backstage for a special meet-and-greet after his Texas show last week (begs29Oct12).

Emma Routh suffers from a rare genetic blood disorder and doctors suspect the disease will worsen over the next few years.

Her grandmother Lisa Routh tells the National Enquirer, "It could lead to cancer at some point, severely shortening her life. She weighs only 32 pounds (14.3 kilograms), but she's full of spunk and, oh, how she loves Justin Bieber!"

And when the kind-hearted Baby hitmaker heard the seven year old's story, he invited the tot and her pals to hang out with him after his Dallas concert on 29 October (12).

The little girl's friend Dawson Beaty gushes, "We all had the best time of our lives!"

This isn't the first time the Baby hitmaker has taken time out of his busy schedule to cheer up a young fan with medical problems - he took cancer-stricken Avalanna Routh out on a date in New York City earlier this year (12) and staged a fake wedding. The six year old died in September (12).

The two girls are not related, even though they share the same last name.