Growth pattern from birth to adulthood in African pygmies of known age

• Published in: Nature communications 2015-07, Vol.6 (1), p.7672-7672, Article 7672
• Main Authors: Rozzi, Fernando V. Ramirez, Koudou, Yves, Froment, Alain, Le Bouc, Yves, Botton, Jérémie
• Format: Article
• Language: English
• Subjects: 631/181/19/2471; 631/181/2474; Adolescent; Adolescent Development; Adult; African Continental Ancestry Group; Biological anthropology; Body Height - ethnology; Body Size - ethnology; Child; Child Development; Child, Preschool; Female; Growth Charts; Humanities and Social Sciences; Humans; Infant; Infant, Newborn; Longitudinal Studies; Male; multidisciplinary; Phenotype; Science; Science (multidisciplinary); Young Adult
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8672

The African pygmy phenotype stems from genetic foundations and is considered to be the product of a disturbance in the growth hormone–insulin-like growth factor (GH–IGF) axis. However, when and how the pygmy phenotype is acquired during growth remains unknown. Here we describe growth patterns in Baka pygmies based on two longitudinal studies of individuals of known age, from the time of birth to the age of 25 years. Body size at birth among the Baka is within standard limits, but their growth rate slows significantly during the first two years of life. It then more or less follows the standard pattern, with a growth spurt at adolescence. Their life history variables do not allow the Baka to be distinguished from other populations. Therefore, the pygmy phenotype in the Baka is the result of a change in growth that occurs during infancy, which differentiates them from East African pygmies revealing convergent evolution. The African pygmies are known for their short stature, yet it is unclear when and how this phenotype is acquired during growth. Here the authors show that the pygmies’ small stature results primarily from slow growth during infancy.