What is Chromosome duplication 15q 11q-13q?
Chromosome 15q Duplication Syndrome (Dup 15q) is a clinically identifiable syndrome which results from duplications of chromosome 15q11-13. These duplications most commonly occur in one of two forms.These include an extra isodicentric 15 chromosome, abbreviated idic 15, or an interstitial duplication 15.
A chromosome 15 duplication is a rare genetic condition in which there is an extra copy of part of the genetic material that makes up one of the body’s 46 chromosomes. Like most other chromosome disorders, this increases the risk of birth defects, developmental delay and learning difficulties. However, the problems that can develop depend very much on what genetic material has been duplicated.
Below is a diagram of Chromosome duplication 15q 11q-13q:
A chromosome 15 duplication is a rare genetic condition in which there is an extra copy of part of the genetic material that makes up one of the body’s 46 chromosomes. Like most other chromosome disorders, this increases the risk of birth defects, developmental delay and learning difficulties. However, the problems that can develop depend very much on what genetic material has been duplicated.
Below is a diagram of Chromosome duplication 15q 11q-13q:
How does the chromosome disorder occur?
Chromosome disorders are usually passed down in the sperm and egg cells. This is part of a natural process and as a parent there is nothing you can do to control it.
Common features of people with Chromosome duplication 15q 11q-13q
PHYSICAL ISSUES
There is no typical pattern of features, but those seen most commonly include eyes that slant downwards, a small chin and lower jaw, tiny skinfolds across the inner corner of the eyes, unusually placed or shaped ears, eyes that are spaced far apart and a short neck.
Unusual features of hands and feet have been observed. This includes large hands, shortened or incurving fifth fingers, long, clenched or bent fingers, short or ingrowing nails on one or more fingers, webbed toes or toes that override each other and long, narrow hands and feet with prominent big toes.
COMMON DEVELOPMENTAL ISSUES
Gross motor delays
Gross motor delays are common for most young children with Duplication 15q. The age of which children begin to walk is often delayed.
Fine motor delays
Children also have difficulties holding a feeding bottle so to help with this difficulty they often have occupational therapy. Some babies can be expected to have difficulty establishing feeding. They may be unable to suck effectively or to coordinate the actions of sucking with swallowing. Typically the problems will be mild and temporary but some babies will need long-term support feeding through a nasogastric tube.
Nasogastric tubes are small tubes which are often used in newborn babies, infants and children who are having difficulty swallowing and feeding. They allow them to receive liquid nutrition down the tube and into the stomach. They can also be used to give medication.
Gastro oesophageal reflux (GORD, GERD), where the stomach contents return up the food pipe, is fairly common in babies with a chromosome disorder.
Cognitive delays
Most children show some degree of cognitive delay or learning difficulties.
Speech/language delays
Most children are affected by speech and language delays. Expressive language may be absent or very poor. “Expressive Language
is the use of words, sentences and writing to convey meaning and messages to others”. (http://www.childdevelopment.com.au/using-words-and-language)
Sensory processing disorders
Some children have sensory processing disorders. Some children are over or under responsive to sensory input e.g. sound, touch, taste.
Behaviour challenges
Many with Dup 15q have difficulties with behaviour and social communication. This can often improve with age.
Seizure disorders
Over half of all the people with Dup 15q have at least one seizure. The majority of those will have their first seizure before age 5. There are many different types of seizures. There are two main types of seizures: infantile spasms and Lennox-Gastaut Syndrome. During a seizure people might have body spasms (shaking), (head drops or head attacks) – inability to control the movement of the head. Around half the children with a proximal 15q duplication have seizures. Therapy can reduce the severity and frequency in some patients. Recovery from therapy may take several months or even a year
There is no typical pattern of features, but those seen most commonly include eyes that slant downwards, a small chin and lower jaw, tiny skinfolds across the inner corner of the eyes, unusually placed or shaped ears, eyes that are spaced far apart and a short neck.
Unusual features of hands and feet have been observed. This includes large hands, shortened or incurving fifth fingers, long, clenched or bent fingers, short or ingrowing nails on one or more fingers, webbed toes or toes that override each other and long, narrow hands and feet with prominent big toes.
COMMON DEVELOPMENTAL ISSUES
Gross motor delays
Gross motor delays are common for most young children with Duplication 15q. The age of which children begin to walk is often delayed.
Fine motor delays
Children also have difficulties holding a feeding bottle so to help with this difficulty they often have occupational therapy. Some babies can be expected to have difficulty establishing feeding. They may be unable to suck effectively or to coordinate the actions of sucking with swallowing. Typically the problems will be mild and temporary but some babies will need long-term support feeding through a nasogastric tube.
Nasogastric tubes are small tubes which are often used in newborn babies, infants and children who are having difficulty swallowing and feeding. They allow them to receive liquid nutrition down the tube and into the stomach. They can also be used to give medication.
Gastro oesophageal reflux (GORD, GERD), where the stomach contents return up the food pipe, is fairly common in babies with a chromosome disorder.
Cognitive delays
Most children show some degree of cognitive delay or learning difficulties.
Speech/language delays
Most children are affected by speech and language delays. Expressive language may be absent or very poor. “Expressive Language
is the use of words, sentences and writing to convey meaning and messages to others”. (http://www.childdevelopment.com.au/using-words-and-language)
Sensory processing disorders
Some children have sensory processing disorders. Some children are over or under responsive to sensory input e.g. sound, touch, taste.
Behaviour challenges
Many with Dup 15q have difficulties with behaviour and social communication. This can often improve with age.
Seizure disorders
Over half of all the people with Dup 15q have at least one seizure. The majority of those will have their first seizure before age 5. There are many different types of seizures. There are two main types of seizures: infantile spasms and Lennox-Gastaut Syndrome. During a seizure people might have body spasms (shaking), (head drops or head attacks) – inability to control the movement of the head. Around half the children with a proximal 15q duplication have seizures. Therapy can reduce the severity and frequency in some patients. Recovery from therapy may take several months or even a year
Treatment
Currently, there is no specific treatment that can directly address genetic changes seen in people with Dup 15q. However, there are some therapies which may help with the symptoms associated with this condition.