Dyssegmental Dysplasia, Silverman-Handmaker Type (DDSH)
Dyssegmental Dysplasia, Silverman-Handmaker Type (DDSH)
OMIM number: 224410
Comments closing date: 29/08/2025
Silverman Handmaker- Dyssegmental dysgenesis
(DDSH) syndrome is a rare autosomal recessive
disorder cause by a gene change within the
HSPG2 gene on chromosome 1. Couples at risk
have a 25% chance in each pregnancy of having
an affected child. This is a lethal form of neonatal
short limbed dwarfism. Affected children are often
detected during pregnancy as the limb and
skeletal abnormalities are so significant. Those
who reach term usually die soon after birth.
Affected children have multiple skeletal
abnormalities including abnormal shaped spinal
vertebrae, short long bones, bowed lower legs
(talipes), small chin and chest. Due to the small
thorax affected infants have lung hypoplasia
(poorly developed lungs). Affected children often
have a cleft palate, flat face, abnormal ears and
short neck. Additional findings in some children
will be an encephalocoele (external sac protruding
from skull containing brain tissue), cardiac and
renal malformations. This condition is always
lethal and often results in loss of a pregnancy due
the extent of the abnormalities. There is no cure
for this condition.
Review date: 25 July 2027
