Mosaic Down Syndrome is a genetic condition in which a person is born with an extra copy of chromosome 21 in some cells, affecting less than 1% of those with Down syndrome.

Medically reviewed by Brigid Dwyer, MD Mosaic Down syndrome is a variant of Down syndrome. Down syndrome is a congenital ...

Turner syndrome is a chromosomal condition involving a person’s sex chromosomes. It is considered mosaic when an X chromosome is missing in some cells in people who have two X chromosomes.

Zambelli was diagnosed with Mosaic Down Syndrome at the age of 23, while 28 weeks pregnant. This combined image shows Ashley Zambelli, 23, left, and Zambelli with her daughter Lillian, right.

A mum who was diagnosed with Down’s syndrome aged 23 says people “don’t believe” she has the condition. Ashley Zambelli was diagnosed with mosaic Down’s syndrome in February 2023 after ...

When Hunter syndrome affects the brain, which is about 75% of the time, symptoms usually show up between 18 months and 4 years of age. They start about 2 years later when the disease is milder.

SOX2 anophthalmia syndrome: This condition is rare, but when it does occur, it can cause a child to be born without eyes and experience seizures, brain development issues, and delayed growth.

Explore REGENXBIO's RGX-121 gene therapy for Hunter syndrome, with an FDA decision due Nov 9, 2025. Click here to read my most recent analysis.

Hunter syndrome is rare and the trial is small, so there are no pre-defined standards for the safety endpoints to be compared against, Denali said. Related.

With an FDA approval submission for RegenXBio’s Hunter syndrome gene therapy already underway, the biopharma has now found a commercialization partner for both the U.S. and Asian markets.. That ...