. The term
"achodroplasia"
is inaccurate because it denotes "lack"
instead of abnormal
cartilage.
More accurate are the terms
"chodrodysplasia" or
"chondrodystrophy" which imply abnormal
cartilage tissue formation and sustenance but these terms
apply to many other disorders in addition to achondroplasia.
In summary, the "erroneous" term "achondroplasia" is for
the time being the most precise choice given that the
etymology or "the idea" in the term is disregarded.
Extract from a Classic Description
(Note: this represents a sample of "classic" writing
style blending history, arts, and
"humanism" without
an overemphasis on "advances", the "now" and the "me" in
an effort to help a reader to gain a perspective thus
facilitating the assimilation of a
complex subject.)
"... A limestone statuette of Chnoum-hotep from about
2700 BC shows a man with a large head, diminutive lower
limbs, sort digits and upper limbs,
lordosis and good
muscular development. This individual had normal
intelligence because he was "chief of the Perfumes" or
"Head of the Wardrobe. Other achodroplastic dwarfs in
Egypt were in charge of pets or jewelry ...
Good mental development and provocative wit in a person
with somewhat grotesque physical features made these
dwarfs valuable adjuncts of a princely household ...
the demands for achodroplastics was at times greater than
the supply, so that increased production was attempted ...
done by dwarf marriages ... by deficient diets
imposed on children ... it became customary to have paintings made
of successful court dwarfs ...
(Note: Ms Maria Barbola by Velasquez in "Las Meninas" in
the companion illustration.)
(Note: Peter "the Great" of Moscov and founder of the
"Empire of all Russians" was a great imitator and
had a propensity toward excesses - he "encouraged" marriages
amongst dwarfs - the high prenatal mortality of dwarfed
mothers and their newborns later led to the banning of such
marriages in the Empire.)
... The best description of an achondroplastic dwarf
was given - before Parrot - in David Copperfield by Dickens,
who described Miss Mowcher ...
Achondroplasia or better chondrodystrophy, is known to
occur in animals in many forms. It can affect the entire
skeleton or only parts of it ...
Tux-Zillertal cattle ... Peking-ese and French bulldog are
examples of generalized chondrodystrophy, whereas in Niata
cattle and Yorkshire swine the anomaly is limited to the
head ... dachshund ... the extremities are shortened and
the head and spine are normal ...
... Porak described the first hereditary instance (of
achondroplasia) ... (a review) prior to 1912 (of 80
pedigrees showed that) 55 were solitary cases and
25 (pedigrees had) more than one case ... in 14 (pedigrees
there were) two or more generations (were affected) ...
Morch concluded that in the familial cases the disorder
was transmitted as a dominant character ... the
sporadic
(or spontaneous
cases were due to mutation; they were
potential initiators of families in which about 50% of the
offspring would have been affected ... the possibility of
recessive inheritance was denied by Morch ... Concordance
has been observed in identical twins and discordance in
nonidentical twins ...
The results of matings of two achondroplasts are of great
interest ... the pregnancies ... are terminated prematurely
... (the fetus who inherits the achodroplasia gene from
both parents ["double hit"] manifests a more severe and
lethal skeletal dysplasia named "achondrogenesis", the
matter is further complicated since the same mutated
gene
can cause diverse phenomena
or phenotypes, in short "achondroplasia type of chondrodystrophy is for the time
being the most precise label for this sort of disorder) ...
Advanced parental age (paternal
in particular) has been known
to be an etiologic factor in achondroplasia since 1912 ...
Penrose found and Murdoch confirmed that paternal age is the
major factor in the origin of new mutations of achodroplasia.
... if the mother is dwarfed, the birth weights are lower ...
In the newborn, the head is of normal size but there are
frontal and parietal eminences and the root of the nose
is depressed.
The bones of the skull are of normal hardness and
the fontanelles and sutures of normal width.
The trunk is of almost normal size but the ribs are flaring
and a rosary can be felt at the costochondral junction.
The limbs are short, thick and curved.
In some patients the skin appears too large for the size of
the bones ... "like an accordion" ...
Achodroplastic dwarfs often can be recognized at a glance
by their short extremities, which are attached to a
relatively large trunk, and by the large head and typical
facial features. The forehead is high and bulging. The root
of the nose is broad and depressed and the features are
coarse. The mandible is disproportionately large and the
chin protruding. The palate is high and malposition of
teeth frequently is present. The chest, although of nearly
normal length, is contracted in the anteroposterior diameter.
A ridge formed by prominent costochondral junctions may be
visible. The abdomen
is prominent. An exaggerated lumbar
lordosis and
prominence of the buttocks are characteristic ...
In addition ... lumbar lordosis (is common) ... scoliosis is
rare ... the height of the vertebral bodies appears reduced
and the intervertebral spaces enlarged ... lumbar bodies
taper in width and with this goes a narrowing of the lumbar
spinal canal ... may lead to neurologic complications ...
spinal cord and cauda equina ... can be compressed easily ...
Pelvic changes are of great biologic importance, ... inability
of female achodroplastics to deliver without expert help ...
With the arms hanging at the sides, the fingertips usually do
not reach below the major trochanter of the
femur.
The shortening
is more marked in the proximal than in the distal tubular bones
(rhizomelia). The wrists and ankles often are prominent owing to
terminal spread of the bones ...
The hands and feet are short and broad. Sometimes there is a
divergence of the third and fourth fingers whereby a "trident"
hand is formed. Coxa vara frequently is present and the feet
are turned inward, which explains the waddling gait so
characteristic of achondroplasia ...
Although achondroplastic dwarfs usually can be recognized at
a glance, they do not represent as uniform a disease picture
as is generally assumed ...
The mental and artistic faculties ... should be developed.
Today, there exist many more specialties in which the brain
rather than the length of the extremities counts.
from Josef Warkany, Congenital Malformations,
Year Book Publishers, 1971.
Achondroplasia pages
for health care providers
