Siblings with world’s only known genetic defect find hope for DNA in US
Lily Arnott, five, and her brother Benjamin, 3, from Penicuik, were both born with an extra chromosome, made up of unequal parts of chromosomes 21 and 16.
They are believed to be the only people in the world with such a unique chromosomal disorder that there is no name for it.
Due to chromosome imbalance, Lily and Benjamin have an overall developmental delay, learning disabilities, and hypermobility with their condition most similar to Down syndrome.
Both still wear diapers, have difficulty communicating verbally, and have various health complications. Lily is prone to kidney infections and Benjamin has a similar challenge with lung infections.
Now a ray of hope has been offered to parents Kenny, 42, and Crystal Arnott, 38, after they signed up for an international database that helps locate and match families with extremely rare chromosomal and genetic disorders. .
The Arnott’s are among 684 Scottish families who have signed up for the database, run by the Surrey-based charity Unique.
Although a complete match has not been found, the family has been linked to four people in America who suffer from similar chromosomal disorders.
Among them is a 27-year-old man from the United States who the Arnotts claim will help them begin to piece together the puzzle of Lily and Benjamin’s development.
Mr Arnott said: “Since our children are the only people in the world with this genetic makeup, we have no way of assessing their development.
âTalking to families who have similar, possibly older children could help us determine which path they might take.
âRegular milestones mean nothing to us, but it will hopefully give us part of the puzzle and help give us a better idea of ââwhere our kids should be.â
Mr Arnott praised their local elementary school and support services for the “excellent support” provided, but said “it can be lonely” being the only family in the world living with this rare genetic condition.
âWe have had dark days,â he said.
The father added: âIt was really difficult when it was first confirmed. The genetic counselors were great but couldn’t tell us what the long term outcome would be for Lily and Benjamin. Every day we learn as we go.
Despite their uncertain future and medical complications, Lily and Benjamin are full of character and fun.
For now, Mr. and Mrs. Arnott are taking each day as it comes, enjoying their children as they are while hoping that genetic pairing will bring them more answers.
Ms Arnott said: “They are so much fun, Lily loves her princess dresses and dancing and Benjamin is just a typical little boy who likes to get dirty and crawl around cardboard boxes.”
âLooking at our children is like looking at any other child, itâs only when they start to walk and talk that you can tell they are different,â Arnott added.
“We don’t know what Lily and Benjamin’s future looks like, but right now they’re just a five and three year old enjoying life, which is what we want it to be.”
What is Lily and Benjamin’s unnamed chromosome disorder?
Before Lily was born in 2015, Mr. and Mrs. Arnott suffered a series of miscarriages whose genetic tests were linked to a chromosomal defect – known as a “balanced translocation”.
Although normally harmless, the balanced translocation can lead to conception problems and increases the risk of duplicating or missing chromosome pieces in the offspring. This can sometimes lead to learning disabilities, developmental delays and health problems.
When Lily was born in 2015, her parents noticed that she was missing key developmental milestones and took her for genetic testing.
The results showed that she had an extra strand of chromosome – in addition to the 46 strands that normally make up the 23 pairs – which included a large portion of her maternal chromosome 21 and a shorter portion of maternal chromosome 16.
The family received these test results when Ms Arnott was already pregnant with Benjamin who was tested after birth. The results showed that he shared the unusual genetic arrangement of his older sister, making him the only two recorded cases in the world.