Diagnosis code is a tool used to group and identify diseases, disorders, symptoms, injuries and other reasons for patient encounters. Diagnostic coding is the translation of written descriptions of diseases, into codes from a particular classification.
Diagnostic codes are responsible for determining and classifying diseases, as well as symptoms, complaints, external causes, signs, abnormal aspects, and social circumstances for illness or injury. This allows standardization of disease nomenclature, allowing effective communication between health professionals helping to avoid ambiguities that could be harmful to the patient, for example.
In the case shown in the question above, the diagnostic code that would be used for ossium fragilitas, osteogenesis imperfecta and osteopsatirosis would be Q78.0.
The trait that first appears or is visibly expressed in the organism is called the dominant trait. The trait that is present at the gene level but is masked and does not show itself in the organism is called the recessive trait.