This portrait, the first of five, shows SIGNS that render the face characteristic. Since recorded history, it was recognized that infants with such faces (FACIES), often were mentally retarded and were branded as "mongoloid cretins" and since some 200 years they were also categorized as having Down syndrome (DS). In Medicine, SYNDROME refers to a consistent combination of concurrent signs. Since 1950's it is known that an additional important diagnostic component of DS is the presence of trisomy 21.
Irrespective that the diverse artists that produced the five portraits did not have medical eduction, they did note many DYSMPORPHIC SIGNS (artists have trained eyes). It is reasonable that clinicians should also educate their eyes and not only be able to detect SIGNS but metamorphose them in SIGNALS and SYNDROMES. Such process accelerates the diagnosis and grasp of etiology and pathogenesis. SYNDROMOLOGY is a component of the discipline of DYSMORPHOLOGY.
Note that we rely on DS as an example to underscore concepts of SIGN > SIGNAL > SYNDROME > ETIOLOGY > PATHOGENESIS ... Particular dysmorphic signs are not emphasized at this point - the emphasis is on the whole face which is a FACIES and which is the SIGNAL.
Please view this and the rest of the portraits repeatedly - when you become familiar with them, you probably will recognize DS anywhere.