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A lethal neonatal syndrome characterized by
chondrodystrophy, micromelic dyssegmental dwarfism, vertebral and
metaphyseal abnormalities, advanced carpotarsal ossification, dislocation of
the patellae and hips, glaucoma, and mental deficiency. Prognosis is poor.
++
Dyssegmental Dwarfism Rolland-Desbuquois type;
Dyssegmental Dysplasia Rolland-Desbuquois type; Anisospondylic
Campto-Micro-Melic Dwarfism.
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Autosomal recessive transmission.
++
Evidence for possible deficiency of alpha-1 chain
in collagen peptides. This may be responsible for increased cross-linking
and abnormal collagen stiffness.
++
Clinical features (micromelia, limited joint mobility
associated with cardiac and neurological anomalies) and radiological
features (symmetrical short extremities, shortened trunk length, and narrow
thorax). Gel electrophoresis shows abnormal collagen pattern. Chromosomal
study is usually normal.
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Clinical features can involve skeleton (short,
thick, bowed long bones; marked metaphyseal flaring and cupping; abnormal vertebrae
with different sizes, thicknesses, and widths that may consist of two or
more separate ossified masses; narrow thorax with horizontal ribs; reduced
joint motility), and CNS (hydrocephalus, occipital encephalocele). Other
occasionally reported features include hydronephrosis, hypertrichosis, and
congenital heart defect in one case. In severe cases (also classified as
Silverman-Handmarker Syndrome), death usually occurs within few days or
weeks of birth. Even in milder form, survival beyond the first year of life
is rare. Cause of death is usually respiratory related.
++
Evaluate the airway for potential
difficult tracheal intubation (clinical, radiographs). Assess respiratory function
(clinical, chest radiograph, arterial blood gas), oxygen, and ventilatory requirement.
Assess neurological status, which might include clinical and CT scan for possible
hydrocephalus and raised intracranial pressure.
++
No reported experience. The potential for
difficult airway management is present because of the flat face, small mouth, and
short neck. There is a significant risk for difficult lung
ventilation because of the narrow thorax and poor lung compliance. The requirement for
postoperative ventilatory monitoring or support may be indicated. Intravenous access may be
difficult because of the skin condition. Poor joint motility may be prone to pressure
necrosis and require careful intraoperative positioning.
++
Muscle relaxants should
be avoided until airway is secured and lung ventilation confirmed. Prophylactic
antibiotics are indicated in case of cardiopathy. Opioids should be used carefully because
of the increased respiratory risk. Avoid succinylcholine in the presence of glaucoma.
++
Silverman-Handmaker Syndrome (Dyssegmental Dysplasia): Lethal form of
neonatal short-limbed dwarfism. Clinical and radiological features include
chondrodysplasia with dyssegmental ossification of the spine. The term “dyssegmental
dysplasia" refers to differences in size and shape of the vertebral bodies
(anisuspondyly).
Aleck K, Grix A, Clericuzio C: Dyssegmental dwarfism: Clinical,
radiographic and morphologic evidence of heterogeneity.
Am J Med Genet 27:295, 1987.
[PubMed: 3605216]
Gruhn J, Gorlin R, Langer L: Dyssegmental dwarfism: A lethal anisospondylic
camptomicromelic dwarfism.
Am J Dis Child 132:382, 1978.
[PubMed: 645657]