MONGOLISM. — Mongolism or Langdon-Down syndrome (1866) is a condition of marked congenital but non-hereditary physical and mental developmental delay; it takes its name from the fact that the faces of affected children resemble the Mongolian type. Curschmann (1938) distinguished two varieties: malese and esquisce.
At birth, mongolism occurs at a rate of about 1 per 1,000, without distinction of race, social class, or sex. Among the ancestors, syphilis and tuberculosis are frequent, while mental and nervous tares appear rarer. The influence of the relatively advanced age of the mother is well known; often the mongol is the youngest of a large family. The cause of this growth disorder (auxopathy) may still be said to be unknown despite the various hypotheses advanced.
Anatomo-clinical aspects: small cerebral hemispheres, with simple and coarse convolutions and a wide Sylvian fissure (thin cortex poor in cells, poor development of tangential fibres); thyroid often normal; pituitary gland deficient in eosinophilic cells; almond-shaped eyes with narrow palpebral fissures and epicanthus (vertical skin fold) at the inner canthus (with frequent blepharitis, strabismus, myopia); flattened cheekbones; small mouth, held half-open, with thick lips; large, furrowed tongue; teeth altered in shape and development; ogival palate; broad, flattened nasal root; upper part of the auricle strongly flattened; frequent microbrachycephaly; stature below normal; during infancy, marked muscular hypotonia with great joint laxity, which regresses with age; umbilical hernias are frequent; marked hypogenitalism, while hypothyroidism is observed only in mixed types (mongolism + myxedema); delayed walking. Mentally: oligophrenia generally remaining within the limits of imbecility, i.e., a mental age below 9 years; speech always defective, agrammatical, and poor; affectivity fairly well developed, attention very labile; weak memory. In general, the patient remains little receptive to discipline and instruction; exceptionally, intelligence may reach the level of “feeblemindedness.”
Mortality is high: 50% of mongols die in the first year of life, only a quarter reach puberty, and only 10% to 25% reach the age of 25; death is most often due to an affection of the respiratory tract, especially tuberculosis, to which the mongol appears particularly prone. Mongolism is little or not at all affected by medical or pedagogical treatment. The capacity to understand and to will, and correspondingly legal and moral responsibility, are proportionate to the degree of mental impairment (v. FRENASTHENIA).