What causes CHARGE SYNDROME?

It's an extremely rare congenital abnormality my little sister was born with it she's 4 eats with a g-tube and is the size of a 6 month infant she cannot hear. Each letter in her syndrome means something. Each letter in charge stands for each one of her problems that make up her syndrome. It's really sad nobody else in my family has it and when my mom was pregnant no tests detected it. She found out when she was born blue. She can miracoulously see thanks to God she wasn't supposed to see but she cant sit up she's like a tiny infant she just doesn't grow.