DWARFISM Flashcards
what is dwarfism?
short stature
height-vertex below 2SD or in 3rd percentile for given age and sex
generally- adult height of 4 foot 10 in (147 cm) or less
what does dwarfism result from?
medical condition or genetics
what 2 categories is dwarfism put into?
disproportionate- present at birth or in early infancy; most common type is achondroplasia -> normal size torso and short limbs
proportionate- not immediately apparent; d/t growth hormone deficiency-> pt smaller than average all over
what is the etiology of dwarfism?
four bullet points
- familial short stature (FSS)
- low-normal height velocity throughout life
- matches parental height (child is short like their parents - constitutional delay of growth and puberty
- short height in childhood, but attainment of target height in adulthood; “late bloomer” - idiopathic short stature (ISS)
- short stature with no other etiology (endocrine/metabolic) can be determined - endocrine disorders
- growth hormone deficiency (GHD) or growth hormone insensitivity
bone disease etiology of dwarfism?
- achondroplasia- 90% dwarfism- auto dom where theres inhibition of chondrocyte proliferation -> impairment of endochondral bone formation
- spondyloepiphyseal dysplasia: primarily involves vertebrae and proximal epiphyseal centers
systemic disease etiology of dwarfism?
systemic dz has 2ndary effect on growth
- undernutrition, juvenile idiopathic arthritis, IBD, celiacs, CKD, pulm/cardiac/immunologic/metabolic dz, cancers, glucocorticoid therapy
what is proportionate GH deficiency exactly?
pituitary gland fails to produce adequate supply of growth hormone
-can be congenital or acquired
what are signs of proportionate GH deficiency?
- height below 3rd precentile on standard pediatric growth charts
- growth rate slower than expected for age
- delayed or no sexual development during teen years
what are features of proportionate GH deficiency?
head, trunk. and limbs are all proportionately small
poor development of organs
which of these is most common form of dwarfism?
achondroplasia
what are the clinical features of the body in achondroplasia?
average sized trunk
short arms and legs, particularly noticeable in upper arms and thighs
short fingers, often with wide separation between middle and ring fingers (trident hand)
limited mobility at elbows
what are the clinical features of the head in achondroplasia?
disproportionately large head with prominent forehead and flattened bridge of nose
what is a very specific but important characteristic of the legs in achondroplasia?
progressive development of bowlegs
what are the last 3 miscellaneous clinical features of achondroplasia?
protruding jaw (sometimes poor dental structure), progressive exaggeration of lumbar lordosis, decrease in muscle tone (hypotonia) and loose joints
when can disproportionate dwarfism be suspected?
during a prenatal US where very short limbs disproportionate to the trunk can be seen
in this case you then go on to genetically test by chorionic villus (cvs) sampling or amniocentesis