Table 1.

Variation in Chrd-/-;Nog+/- neonatal defects

Phenotypic groupRelative frequency
Midline class 14 (53%)
Single nostril9 (35%)
Proboscis and synopthalmia/cyclopia4 (15%)
Cleft palate1 (4%)
Truncation class 4 (15%)
Jaw class 8 (31%)
  • Frequency of rostral phenotypes calculated from a subset of 26 affected Chrd;Nog neonates from consecutive outbred litters. Mutant pups containing more than one type of defect were classified according to the most severe defect.