Crying cat syndrome, also called Cri-du-chat or 5P syndrome, is a genetic condition where your baby is born with a deletion on the short arm of chromosome 5. The condition is rare and occurs in only about 1 in 20,000 to 1 in 50,000 newborns. Yet, it is one of the most common syndromes caused by chromosomal deletion.
Like its name implies, the syndrome makes infants produce a high-pitched cry similar to a cat. (“Cri-du-chat” means “cry of the cat” in French.) The cry is caused by an abnormal development of your child’s larynx due to the chromosome deletion. The syndrome is more noticeable as your child ages, but becomes difficult to diagnose past the age of two.
Crying cat also carries many disabilities and abnormalities. A small portion of infants with crying cat syndrome is born with serious organ defects or other life threatening complications that can result in death. Most fatal complications occur before a child’s first birthday.
Children who reach the age of 1, though, generally have a normal life expectancy. Still, your child will most likely have lifelong physical and/or development complications, and these will depend on the severity of the syndrome.
The good news: about one-half of children with crying cat syndrome learn enough words to communicate, and most grown up to be happy, friendly, and sociable.
The exact reason for the chromosome 5 depletion is unknown. In most cases, though, the chromosome break happens while the parent’s sperm or egg cell is still developing. When fertilization occurs, your child develops the syndrome. About 80 percent of affected children experience chromosome deletion that comes from their father’s sperm.
This break is usually so rare it is unlikely to happen again should you and your spouse have another child. However, if you have a family history of crying cat syndrome, your unborn child has a slightly increased risk of being born with the condition. Approximately 10 percent of cases are inherited from a parent.
The severity of your child’s symptoms depends on how much genetic information is missing from chromosome 5. Some symptoms are severe while others are so minor they may go undiagnosed. The cat-like cry, which is the most common symptom, becomes less noticeable over time.
Children born with crying cat are commonly small at birth. They may also experience respiratory difficulties. Besides the namesake cat cry, other distinctive physical features include:
- small chin
- unusually round face
- small bridge of the nose
- folds of skin over their eyes
- abnormally wide-set eyes (ocular or orbital hypertelorism)
- abnormally shaped or low-set ears
- a small jaw (micrognathia)
- partial webbing of the fingers or toes
- single line on the palm of the hand
- an inguinal hernia (a protrusion of organs through a weak area or tear in the abdominal wall)
Internal problems are common too. Children can have skeletal problems like scoliosis (abnormal curvature of the spine), heart or other organ defects, poor muscle tone (during infancy and childhood), or hearing and vision difficulties. As they grow, they often experience trouble talking, walking, and feeding, and can have behavioral problems, such as hyperactivity or aggression.
Children also may suffer from severe mental retardation (the syndrome accounts for about 1 percent of those with mental retardation). However, if your child does not experience defects with major organs or other critical medical conditions, their life expectancy is average.
Doctors usually diagnose crying cat syndrome at birth, based on physical abnormalities and displayed symptoms. Your doctor may also perform an X-ray on your child’s head to detect abnormalities in the base of the skull
To confirm a diagnosis, a chromosome test often will be performed. A specialized technique called a FISH analysis may be used to help detect small deletions. If you have a family history of crying cat, your doctor may suggest a chromosome analysis or genetic testing while your child is still in the womb. The doctor can either test a small sample of tissue from outside the sac where your child develops, (known as CVS or chorionic villus sampling) or they may test a sample of amniotic fluid.
There is no specific treatment for crying cat syndrome. You can help manage the symptoms with physical therapy, language and motor skill therapy, and education intervention.
There is no known way to prevent crying cat syndrome. If you have a family history of the syndrome, even if you don’t display symptoms, you still may be a carrier, and should consider a genetic test.
You also may carry a type of defect called a balanced translocation, which is a defect in the chromosome that does not result in the loss of genetic material. However, if you pass the defective chromosome to your child, it may become unbalanced, which results in the loss of genetic material and can cause the syndrome.