What is skeletal dysplasia?
Skeletal dysplasia is the medical term for what many people
refer to as dwarfism. It’s an umbrella term that includes hundreds of
conditions that can affect your child’s bone and cartilage growth. Types of
skeletal dysplasia are generally classified by which parts of the skeleton are
If your child is born with skeletal dysplasia, they will
have abnormal differences in the size and shape of their legs, arms, trunk, or
skull. They may be very short in stature. They may also have arms and legs that
aren’t in normal proportion with the rest of their body.
Skeletal dysplasia is a genetic condition. It’s caused by a
defect in a specific gene, known as a genetic mutation. Each type of skeletal
dysplasia is relatively rare. But as a whole, skeletal dysplasia affects close
to one in every 5,000 births, report researchers in Genetics
What are the symptoms of skeletal dysplasia?
Specific symptoms of skeletal dysplasia vary depending on the
disorder that your child has. Their arms, legs, trunk, or skull will likely
develop with an unusual shape, size, or both. Other symptoms can include:
- stubby fingers
- duplication of fingers or toes
- club feet
- missing limbs
- missing ribs
- fractured bones
- joint pain
- developmental delays
- cognitive impairments (previously known as mental
What causes skeletal dysplasia?
Skeletal dysplasia is an inherited condition. It can be
caused by many different types of genetic mutations, which are passed down from
parents to children. These mutations can prevent your child’s bones from
growing normally. While skeletal dysplasia runs in families, you can
potentially pass the condition to your child even if you don’t have a known
family history of it.
The exact genetic defect responsible for your child’s
skeletal dysplasia may be difficult to pinpoint. The most common type of skeletal
dysplasia is called achondroplasia.
It’s caused by mutations of your child’s FGFR3 gene. Most of the time, parents
of children born with achondroplasia have normal height and stature.
Other common types of skeletal dysplasia include:
- thanatophoric dysplasia,
a condition that causes your child to develop extremely short limbs, extra
folds of skin on their arms and legs, and underdeveloped lungs
- hypochondroplasia, a
condition that affects the conversion of cartilage into bone in your
child’s body and results in short arms and legs, as well as hands and feet
that are short and broad
- campomelic dysplasia, an often fatal condition in
newborns that causes dangerous bowing of the long bones in your child’s legs
and often their arms as well
- osteogenesis imperfecta, a disorder that results in
fragile bones that break easily
- achondrogenesis, a disorder that causes your child to
develop short limbs and a small body
How is skeletal dysplasia diagnosed?
If your child has skeletal dysplasia, they may be born with
a short stature. In other cases, they may be born with a normal stature and
fail to grow later on. You or your child’s doctor might discover their
condition if your child’s head grows out of proportion to the rest of their body.
To diagnose skeletal dysplasia, your child’s doctor may
first conduct a physical examination. They will likely measure your child’s
height, weight, and head circumference. They will probably measure the lower
and upper segments of your child’s body separately to assess their proportions.
They may also ask you questions about your child and family’s medical history.
Your doctor may use X-rays, magnetic resonance imaging (MRI)
scans, or computed tomography (CT) scans to help identify and assess
deformities in your child’s bones. In some cases, they may even diagnose
skeletal dysplasia before your child is born, using an ultrasound examination. Your
doctor will likely conduct a routine ultrasound during your pregnancy or your
partner’s pregnancy. During the exam, they may notice abnormalities in your developing
child’s bone structure or limb lengths. They may order a more detailed follow-up
ultrasound to help diagnose their condition. The exact type of dysplasia may be
difficult to diagnose until after your child is born.
Your child’s doctor may also recommend genetic and molecular
analysis to help identify the type of skeletal dysplasia that your child has.
This can help them identify the exact genetic mutation that’s causing their condition.
How is skeletal dysplasia treated?
Your child’s doctor may work with a team of specialists to
develop and deliver a treatment plan. For example, these specialists may
include neurosurgeons, neurologists, orthopedists, ophthalmologists,
endocrinologists, radiologists, geneticists, physical therapists, occupational
therapists, and others.
Your child’s doctor may prescribe growth hormones to help
boost their growth. This type of treatment involves injections with needles
every day. It may help increase your child’s height, but they will probably
still develop below-average stature, even with treatment.
Their doctor may also recommend surgery. For example, if
your child’s bones are constricting their spinal cord or brain stem, a
pediatric neurosurgeon may need to remove some bones. Surgery may also be used to
help lengthen your child’s limbs and induce bone growth. But there are many possible
complications involved in this type of surgery. It may involve multiple
procedures and a long recovery period.
Your child’s doctor may also recommend other treatments and
rehabilitative therapies to help relieve their symptoms, increase their
independence, and improve their quality of life.
What can be expected in the long-term?
The long-term outlook for your child will depend on the type
of dysplasia they have. According to the Children’s
Hospital of Philadelphia, about half of fetuses with skeletal dysplasia are
stillborn or die shortly after birth. Some children with the condition survive
into childhood. Others survive into adulthood. Many of them live relatively
Ask your doctor for more information about your child’s
specific condition, treatment options, and long-term outlook.