March 28, 2008

"Midget" Birth Length

Stupid Question ™
Aug. 16, 2001
By John Ruch
© 2001

Q: Are midgets born small, or do they start out average-sized and then stop growing?

A: It’s hard to generalize here because dwarfism is a symptom of 200 to 300 various medical syndromes. Little People of America, a support group for people with dwarfism, defines the condition as a height stunted at 4 feet 10 inches or shorter due to a medical condition. (African Pygmies, for example, are that short, but not as a symptom of a medical problem.)

“Midget” is a term, now considered offensive, for a specific type of dwarfism in which all the body parts are small, but in normal proportion. (In most dwarfism, the thorax is average in size but the limbs are shorter and the head is larger.)

Called ateliosis, it’s a symptom of growth hormone deficiency (sometimes known as hypopituitism, since it involves a lack of hormones from the pituitary gland). It can be genetic, caused by disease or injury, or all of the above.

Ateliosis is an uncommon form of dwarfism, affecting perhaps 10,000 to 15,000 people in the US. However, the shortest people known to history have been ateliotic. The absolute shortest for whom there is reliable evidence was Pauline Musters, born in 1867 in the Netherlands, who reached an adult height of 23.2 inches and a maximum weight of 9 pounds. The average person with dwarfism is twice that height.

Speaking very generally, people with dwarfism have a normal birth length (in the range of 18 to 20 inches), with growth slowing only months or years later. However, short birth length is a characteristic of the rare Russell-Silver and Noonan syndromes, which have dwarfism as a symptom.

Reports are strangely conflicting over whether ateliotic infants are noticeably shorter at birth. However, it seems likely that in most cases they have a normal birth length.

A 1999 University at Buffalo study found that infants with genetic ateliosis have a normal birth length and experience a growth decrease only around 6 months of age. It suggests that growth in the womb is controlled mostly by the mother’s nutrition; dwarfism only sets in when the baby’s own deficient growth hormones take over after birth.

A normal birth length is also indicated by the fact that ateliosis is infamously difficult to diagnose. Growth can be normal as late as 3 years of age before slowing or halting, depending on the degree of hormone deficiency. That’s why pediatricians like to regularly measure children’s height.

All that being said, many of the shortest people in history reportedly did have short birth lengths. Musters was reportedly 11.9 inches at birth, and lengths as low as 9 inches are on record for some ateliotic infants.

However, these are extreme examples and probably involve various complications, possibly including disease, malnutrition and premature birth. It’s quite likely that average birth lengths were shorter in past centuries due to malnutrition. Better nutrition is also why modern ateliotic adults tend to be taller than those of the past.

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