10 Preiser, Davenport: Multiple Neurofibromatosis
the fact that a disease like his own occurs in other members of the family is apt to be denied (if indeed recalled) by the patient under the stressful conditions of the examination; the patient often exhibits the reactions of the malingerer. In a few histories like that of Fig. 29, II, 2, it seems probable that a generation is actually skipped. This is by no means fatal to the view that the disease depends upon a dominant trait, for a precisely similar result is obtained in experimental breeding of clear dominant traits, e.g., in polydactylism of fowl. Occasionally a dominant trait simply fails of expression in an individual who carries it.
Table 1. - Proportion of Fraternity Affected With Neurofibromatosis.
[chart]
No.&Total.&Affected.
7&2&2
8&7&2
10&4&3
11&2&2
12&11&1
17&6&4
18&2&2
19&3&1
21&4&3
21&2&1
23&3&3
24&3&1
25&3&1
26&2&2
27&8&1
29&8&3
29&5&2
29&6&1
29&3&0
30&3&1
31&5&5
31&5&0
32&2&1
33&5&1
33&7&3
34&4&4
&&__&__
Totals&&115&50
[end chart]
6. Special Family Types. In examining comparatively the symptoms shown by different patients one finds a great diversity in them, and also that the special systems exhibited in one member of the family are very like those shown in another member. The resemblances relate to the region preeminently affected, to the nature of the tumors, to the time of their development and so on. Let us consider some examples of these family resemblances in symptoms.
(a) Family Resemblances in Location of Principal Tumors. Since in most cases the tumors are exceedingly numerous it is to be expected that they will sometimes occur in different members of the family in corresponding parts of the body. But apart from this, we have instances in which single exceptional tumors appear in exactly corresponding places, and this frequency must be regarded as significant. Some of these instances are here cited from the literature.
Bruns (1870). The patient was born with a flat tumor of the left temple and left upper eyelid which grew with the growth of his body into a lobed sac hanging over the (not atrophied) eyeball. His brother had a tumor of the temporal region and the left upper