Congenital anomalies are structure formation errors, or disturbed chemical function due to a metabolic deficiency. It is estimated that 1:15 children born today has an inborn defect. Physical anomalies are visible on inspection (overt), or hidden by soft tissue (occult). Common locations for congenital anomalies today are the skull, spine, sacrum, hip, hands and feet. In primitive settings inborn physical or chemical anomalies incompatible with survival are usually eliminated naturally.
Inborn metabolic abnormalities involve utilization of carbohydrates, lipids (fat), pigments, and minerals. Abnormal metabolites may be stored, excreted, or absent. Some deviant metabolic processes are gene transmitted, some are sporadic occurrences.
By definition development is the process of growth and differentiation. Developmental anomalies can appear pre- or post-natally; those after birth can be inborn or from intravital stimulae.
In the past and today in primitive groups inborn and developmental abnormalities were/are attributed to evil influences. In ethnocentric societies inheritance is an accepted explanation. However, clinical observations and laboratory experiments have demonstrated factors that are capable of injuring the fetus and causing abnormalities (teratogens).
Anomalies are inherited through gene transmission (genotype), or are started by some stimulus at the appropriate time in embryogenesis when developing structures are vulnerable (phenotype). Stimuli that can produce phenotype anomalies are physical, chemical, or microbiological. Alteration in formation and development of bone can appear during embryogenesis, or be manifest as dysplasias later during life. Axiomatically, if congenital or developmental abnormalies are in one part of the embryonic body, other structures forming at the same time may also be defective.
A. THE PRESENT
In 18,811 Indian and Eskimo births at USPHS Hospitals July 1964 through June 1966, 174 infants had single malformations that usually involve bone, and 40 had multiple malformations or syndromes that can affect bone. The number of individuals with bone involvement in the latter group was not stated. The rate of congenital anomalies in live births and grossly normal stillbirths was 2.02%. Comparable studies cited showed similar abnormalities in 1.58% White, and 2.44% of Negro live births (1).
The best demographic information about inborn anomalies in Missouri River Basin Native Americans relates to the craniofacial area. In 1963 cleft lip and palate were in 1:276 Montana Native American live births; the general population ratio was 1:583(13). A preliminary field study report (1964) by Tupper and co-workers (14) showed South Dakota Native American school children had manifest lip and/or palate cleft in 1:220, and occult cleft (submucous, bifid uvula) were in 1:149, making the overall rate of occult and overt clefts 1:89.
South Dakota 1981 birth certificate data indicated congenital facial clefting in 1:1105 live births, comparable to ratios in the United States.
Comparison of Adams and Niswander's total data base (3) to Upper Missouri Basin observations was not possible, but using orofacial fusion defects as an index, their results are similar to ours relating to present day regional Native Americans. Adams and Niswander did not refer specifically to facial structures in 21 cases that could have had facial clefting, but the frequency of facial clefts they reported (40/18,811= 1:470) (1) is very close to the rate indicated by the 1981 South Dakota Vital Statistics, and the findings of Tretsven (13) and Tupper (14). At the same time the birth certificate rate for Native Americans was 1:512 (William Johnson, Vital Statistics Division, South Dakota Health Dept., Personal communication, 1982).
The apparent discrepancy between Tupper's findings and the 1981 South Dakota Health Department data are explained by the fact that Tupper's data came from clinical examination, not birth certificate data that frequently are of questionable validity (6).
B. THE PAST
No historical reference was available relating to aberrations in the ancient Upper Missouri River Basin. Hrdlicka (7:167-58,190) reported concerning southwestern U.S. Indians in 1908: "The only instance of congenital abnormalities among the San Carlos Apache learned of by the writer were a harelip and a case of imperforate anus. When a deformity is considerable, the infant is usually allowed to die." This report is especially important because today the facial cleft rate in Apache Indians is one of the highest in the U.S. (G.B. De Blanc, Otolaryngology Dept., USPHS Hospital, Gallup, NM, Personal communication).
A symposium on congenital and developmental anomalies was scheduled for the 1979 annual Paleopathology Association (PPA) meeting, but did not come to fruition for lack of participants (Paleopathology Newsletter No. 26, p. 3). The symposium's failure was interpreted as due to the dearth of exemplary specimens for presentation and discussion. A symposium on this topic occurred at the 1983 PPA meeting. Despite concerted efforts to stimulate interest, only six papers were forthcoming. The unenthusiastic response again reflected the limited stimulus to research, most likely from inadequate "clinical material" with which to work, and around which to build a symposium.
Reasons to explain the disparity between past and present in manifest anomalies might include survival of the fittest, active or passive euthanasia of the deformed with corporeal disposal other than in the communal burial areas, or non-existence. Although the latter supposition is attractive, it is not realistic biologically.
At the first International Congress on Cleft Palate in Houston, Monasterio displayed defective palate crania and figurines depicting facial defects from, Mexico. It was reported that such figurines, and skulls with craniofacial anomalies, were not unusual to central Mexico archaeology, suggesting that affected individuals were assisted to survive, and perhaps revered.
Despite the high frequency of cranio facial anomalies in Native Americans in the Dakota Territory and elsewhere today, few reports of skulls with facial clefts are in the literature pertaining to the Americas. Brooks and Hohenthal (3) described and illustrated three defective palate crania from California.
A Louisiana Caddoan multiple burial contained a 39-44 year old female and a 2-4 year old child, presumed mother and child, both with cleft palate (12).
Gilkey described defective palate crania in the U.S. National Museum. An adult female and a child were from Peru, the third was an adult Pueblo Indian female (5). A fourth cleft palate cranium from Point Hope, Alaska, was reported at the Smithsonian Institution (L. Angel, Personal communication, 1977). Sullivan alluded to a complete unilateral cleft palate skull at the A.I. Dupont Institute in Wilmington, DE. (10).
Berndorfer observed a cleft alveolar ridge in a 500-year-old South Hungary skull (2). Skoog reported a terracotta head from Corinth dating to the fourth century B.C., into which was carved a complete left cleft lip (11). Brothwell and Powers discussed inborn anomalies and their effect upon skeletal populations, and noted that facial clefting was not common in European skeletons (4). Ortner and Putschar (9:246-346), and Manchester (8:206-28,31,32), discussed briefly and illustrated defective palate crania.
Infrequent representation from antiquity in North America is true also for overt and disabling post-cranial anomalies. Ubelaker stated that congenital anomalies are rare in ancient human skeletons (15), but he apparently referred to manifest, disabling disorders, because occult inborn anomalies are frequent.
The most comprehensive analysis for inborn anomalies was performed on the pre-1492 Crow Creek skeletons. Because of skeletal disarticulation and missing or fragmented bones, it was not possible to relate the 385 anomalies to individuals, but obviously a large proportion of the villagers had inborn or developmental abnormalities.
Anomalies in Missouri Basin skeletons were malformations (structural defects from localized morphogenesis error, e.g., spina bifida occulta; genotype or phenotype), or deformations (altered shape and/or structure of previously normally formed parts; usually phenotype). None were anomalads (malformations with subsequent derived structural changes, e.g., Robin syndrome; more commonly genotype), or malformation syndromes (recognized patterns with the same apparent cause, not the consequence of single localized errors in morphogenesis, e.g., Down's syndrome [mongolism]; genotype deformities).
Some disabling anomalies were not obvious until a child lived for an interval. In an aboriginal society such infant could be accepted into the community, and then given life support when the defect became obvious later in life. The few manifest anomalies that were in Dakota Territory skeletons probably were not disabling at birth and were accepted by peers and treated as normal.
In present day Eskimo and Indian newborns recognizable abnormalities involved bone in 214/350 (61%) individuals with anomalies (1). If congenital aberrations occurred in North American aborigines as they do in today's Native Americans, the probability is good that many soft tissue and bone anomalies were in people who lived in the region in the past. For technical reasons (skeletal preservation, mortuary practices, mechanical problems), it has not been possible to look for in ancient skeletons some congenital anomalies involving bone, cited as common in Native American newborns today (clubfoot, polydactyly, syndactyly, atropic fingers, lobster claw hands and feet) (1).
At Crow Creek we found no evidence of congenital disease involving multiple organ systems. We did find regional and local congenital disease.