Genome sequencing cracked the code of Hong Kong schoolgirl’s illness, can solve other diagnosis puzzles

Anna Chu, 10, has struggled with her eyesight since she was born, without even knowing what was causing the problem until three years ago.

After years of failed diagnosis, genome testing eventually discovered a DNA defect she shared with other patients whose details were logged on a global database – revealing her to have Alström syndrome, a condition afflicting only 900 people worldwide.

While the syndrome, according to medical precedent, could completely deprive Anna of her vision by the age of 16, the diagnosis came as a relief for her family, who hope the onset of symptoms can be delayed through treatment.

Her case was held up for inspiration on Wednesday as the leaders of a Hong Kong government-backed project – who were meeting the press for the first time since the scheme’s launch – appealed for patients with undiagnosed conditions to come forward.

Anna’s doctor Brian Chung Hon-yin is now the chief scientific officer of the Hong Kong Genome Institute, an organisation set up in May last year and based in Sha Tin’s Science Park which is hoping to shorten diagnosis periods for patients.

It will recruit 2,000 patients with undiagnosed disorders or hereditary cancer in the pilot phase and 18,000 more with those or other diseases that could benefit from whole genome sequencing in the second phase. Together with their family members, they will contribute some 40,000 to 50,000 DNA samples to the database.

Chung on Wednesday described Anna’s case as the culmination of a “diagnostic odyssey”. Her father Jack Chu said it was “like drifting in the dark ocean with no direction”. “When we received the genomic result, it was like the shore was finally in sight.”

Anna’s disease causes progressive loss to vision and hearing, and is linked with problems such as diabetes, obesity and even issues with heart muscles.