Different genetic variations that disturb the function of ALX1 gene, called ALX1 mutations, have been described in man. ALX1 is a gene that controls many other genes that are involved in the development of face and skull. Exact targets of ALX1 gene is not yet known. During the normal early stages of development of a baby the facial organs begin to form at the both sides of the face with a space in the middle. As these organs develop and grow they come closer in the middle of the face. Nose, palate, and upper lip merge in the middle and become as one and the two eyes come closer. ALX1 is needed for the proper control of these events. One or more of these events can fail and facial organs such as eyes, nose, upper lip, palate, and skull bones may be unable to complete their development if ALX1 gene does not work properly. In most of the cases a special blood test called ALX1 gene sequencing is sufficient to determine the underlying genetic cause of ALX1-related FND. However, for some families other tests may also be required to determine more complicated genetic changes.
An extensive description of the broad clinical spectrum of ALX1-related FND can be found in the Professionals – Molecular characteristics section.