What is Pycnodysostosis?
Pycnodysostosis is a rare genetic syndrome that presents with unique facial features, skeletal abnormalities, and a hardening of the bones. It is a lysosomal storage disorder and is often compared to osteoporosis. There is still a lot that isn’t known about the disease, in terms of its symptoms, and symptoms may vary widely across affected individuals.
The syndrome has currently been reported in 200 people worldwide, but it is possible that the syndrome is underdiagnosed.
This syndrome is also known as:
Maroteaux-Lamy pyknodysostosis syndrome; PYCD; Pyknodysostosis; PKND
What gene changes cause Pycnodysostosis?
Mutations in the CTSK gene cause the syndrome.
It is inherited in an autosomal recessive pattern.
What are the main symptoms of Pycnodysostosis?
The earliest identified symptoms of the syndrome may include a larger skull than normal. This is caused by the delayed fusing together of the joints of an infant’s skull known as sutures.
Unique facial features of the syndrome include a prominent forehead, a pointed nose, a high-arched palate, prominent eyes that are blue, and a small jaw.
Dental issues are also common. These might include the delayed eruption of the baby and permanent teeth. In some instances, teeth fail to develop at all.
Bone anomalies include a malformed collarbone and a breakdown of the bone in the tips of fingers and toes. Fingers may also be smaller than normal with missing fingernails. A hardening of the bones is common with the syndrome. This in turn causes fragile bones, leaving affected individuals more susceptible to fractures. These fractures might be caused by injury or appear without being injured.
Respiratory and sleep issues are also possible symptoms. These are often caused by a malformation of the chest triggered by the syndrome.
A short stature and shorter limbs are also associated with the condition.
Possible clinical traits/features:
Bone pain, Blue sclerae, Absent frontal sinuses, Anonychia, Abnormality of the thorax, Abnormality of pelvic girdle bone morphology, Abnormal palate morphology, Carious teeth, Abnormal fingernail morphology, Abnormality of the clavicle, Abnormality of epiphysis morphology, Persistence of primary teeth, Persistent open anterior fontanelle, Osteolysis, Osteolytic defects of the distal phalanges of the hand, Osteomyelitis, Autosomal recessive inheritance, Brachydactyly, Prominent nose, Malar flattening, Anemia, Delayed eruption of teeth, Delayed eruption of primary teeth, Delayed eruption of permanent teeth, Abnormal pattern of respiration, Abnormality of dental morphology, Increased bone mineral density, Micrognathia, Narrow palate, Narrow chest, Splenomegaly, Ridged nail, Frontal bossing, Proptosis, Wormian bones, Spondylolisthesis, Spondylolysis, Recurrent fractures, Scoliosis, Skeletal dysplasia, Hydrocephalus, High forehead, Cognitive impairment, Hepatomegaly, Short stature, Hypodontia, Short toe.
How is it diagnosed?
To find out if someone has a diagnosis of Pycnodysostosis, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
