Diastrophic in Greek mean twisted or crooked.
Diastrophic dysplasia is a type of
osteochondrodysplasia caused by homozygous
mutation in the gene DTDST (diastrophic
dysplasia sulfate transporter gene).
Abnormalities occurring particularly in the
skeletal and cartilaginous system are typical of
1 in 100,000 live births.
In Finland, 1-2% of the general population are
carriers and a total of 183 cases have been
diagnosed, with a prevalence ratio of 1 in 30,000
Characterized by short stature
Short arms and legs (short-limbed dwarfism)
Abnormal development of bones (skeletal
(Joint dysplasia) in many areas of the body
Progressive abnormal curvature of the spine
(scoliosis and/or kyphosis)
Prominent among these characteristics were
(rhizomelia) of the lower and upper limbs
(shortening of the proximal portions)
Mesomelia (shortening of the intermediate
Both upper limbs showed marked curvature
Thumbs to deviate away (abduction) from the
body ("hitchhiker thumbs")
Clinodactyly of the fifth finger
Abnormal tissue changes of the outer, visible
portions of the ears (pinnae)
In some cases, malformations of the head and
facial (craniofacial) area
Spina bifida occulta
Prenatal ultrasonography findings of diastrophic
dysplasia(a) clubfoot; (b) fifth finger with clinodactyly.
Hypoplasia of the first metacarpal(clinodactyly )
Three-dimensional sonographic features of diastrophic
dysplasia at 23 weeks’ gestation. (a) Facial dysmorphism with
micrognathia and small nose. (b) Shortening of upper limb with
hitchhiker thumb. (c) Short, deformed lower limbs in ‘Buddha’
position and severe talipes. (d) Thoracolumbar kyphoscoliosis.
Respiratory obstruction, including laryngeal stenosis,
may occur in newborns. The mortality rate due to
respiratory distress can approach 25% in early infancy.
Hypoplastic cartilage in the trachea and larynx causes
voice abnormalities and breathing difficulty.
Small Auditory Canals
Small auditory canals are characteristic, but this does
not usually impair hearing. However, deformity of the
middle ear ossicles can result in
Surgery is usually performed before walking age
to correct foot deformities.
Later in life, patients must look out for worsening
foot deformities, progressive curvature of the
spine, and hip pain in early adult life (due to
arthritis). Common surgical procedures intended
to correct these problems include an osteotomy
of the foot or lower leg (to achieve a plantigrade
foot) or hip replacement surgery (for progressive