Syndrome involving a form of primordial dwarfism with
a characteristic facial-head shape (“bird-headed” appearance) and
spongioid microcephaly (called also the Chimpanzee brain). Other clinical features
include large ears, sparse hair, joint defects, clubfoot, trident hands and
Bird-Headed Dwarfism; Nanocephalic Dwarfism;
Microcephalic Primordial Dwarfism; Harper Syndrome; Seckel Nanism;
described in 1960 by Helmut Paul George Seckel, German pediatrician.
Extremely rare; about 40 cases in the literature.
Clinical delineation has been inconsistent and probably only one-third of
reported cases are truly affected and only seven familial cases have been
Autosomal recessive inheritance. Chromosome
instability has been seen in a small subgroup of patients.
Seckel syndrome may be caused by a mutation in the
gene encoding ataxia-telangiectasia and RAD3-related protein, which maps to
chromosome 3q22.1-q24. Another locus for Seckel syndrome has been mapped to
chromosome 18p11-q11. Central nervous system anomalies suggest an underlying neuronal
Clinical supported by imaging of the brain.
Dwarfism, low birth weight. Small head, large
eyes, beak-like nose, narrow face, and receding mandible. Laryngeal
stenosis. Mental retardation, very small brain with agenesis of the corpus
callosum, dysgenetic cerebral cortex, cerebral cysts. Pancytopenia.
Assessment of airway must be conducted for
possible difficult tracheal intubation. The presence of laryngeal stenosis must be
eliminated using imaging if indicated. Case report of intraoperative abnormal
hypertension suggests that renal examination and imaging must be performed.
Direct laryngoscopy and tracheal intubation are
usually not difficult, however, the potential for laryngeal stenosis requires
that smaller than predicted endotracheal tubes must be available. It is recommended to
monitor the arterial blood pressure invasively because of the significant risk of severe
There are no abnormal responses to drugs
reported. Also, patients are not known to have greater sensitivity to narcotics even in
presence of severe microcephaly.
(Osteodysplastic Primordial Dwarfism Type I):
An extremely rare inherited
disorder characterized by low birth weight, dwarfism, microcephaly, and
“beak-like” protrusion of the nose. Other characteristic facial features
include abnormally large eyes, micrognathia, retrognathia, a narrow face,
and low-set ears. Affected children may exhibit mental retardation. This
condition closely resembles Seckel syndrome, except that, in Cephaloskeletal
Dysplasia, the body proportions are abnormal and the limbs are unusually
short and bowed. In Seckel syndrome, the proportions are normal. It is
suggested that the inheritance is an autosomal recessive trait.
Osteodysplastic Bird-Headed Dwarfism Type II
(Osteodysplastic Primordial Dwarfism Type II): An extremely rare
inherited disorder characterized by severe dwarfism, microcephaly,
“beak-like” nose, and various skeletal abnormalities especially the arms
and legs. Low birth weight may be present. Other clinical features include
retrognathia, a narrow face, and dysplastic ears. Mental retardation may
also be present. It is inherited as an autosomal recessive transmission.
Osteodysplastic Bird-Headed Dwarfism Type III
(Osteodysplastic Primordial Dwarfism Type III): Characterized ...