Parental dermotoglyphs in age-independent mongolism.

Penrose and Smith (1966) have estimated that about three-fifths of all clinical mongolism is caused by some process closely related to ageing of the ovum (the age-dependent group), while the other two-fifths (age-independent) includes the socalled hereditary causes and some strongly suggestive instances of environmental origin. The relative proportion of cases in the two classes differs from one country to another and from one study to another. It has also been reconfirmed recently (Sigler et al., 1965) that there exists no statistically significant association between paternal age and mongolism. Inherited translocation mongolism accounts for a small proportion of the age-independent group (Mikkelsen, 1967; Wright et al., 1967). What are other hereditary factors in this group? Why should young mothers deliver mongol children with standard trisomy ? Penrose (1954) noted that mothers showed significant resemblance to the mongol child when the palmar axial triradius was measured in dermal patterns. Furthermore, Penrose and Smith (1966) have presented the view, with supporting evidence, that a percentage of the mothers of mongols are themselves mosaic mongols. In this study we were interested in further measurement of dermatoglyphic data. It was important to determine if parents show additional dermatoglyphic microsymptoms of mongolism, and if they do, is this finding more pronounced in the age-independent group, since this group would not include processes related to ageing of the ovum.