CHICAGO, Oct 10 (Reuters) – When Lianor da Cunha Hillerstrom of Lexington, Massachusetts, learned her now 9-year-old son Oskar had Down syndrome, she was concerned but not panicked.

As a child, Lianor lived for a time in Santo Amaro de Oeiras, Portugal, near her aunt Teresa who had Down syndrome, which causes intellectual disability. Had Lianor, who is 47, stayed in Portugal, she would have witnessed her aunt decline and then die at age 60 of Alzheimer’s – the most common cause of death for people with Down syndrome.

Now, Lianor’s husband and Oskar’s father, former biotech executive Hampus Hillerstrom, 46, is leading an effort to gain parity with neurotypical adults for his son and others with Down syndrome.

That means being able to get them promising new drugs like Eisai (4523.T) and Biogen’s (BIIB.O) recently approved Leqembi and Eli Lilly’s (LLY.N) experimental donanemab, as well as inclusion of people with Down syndrome in clinical trials of treatments for Alzheimer’s.