HHAT

Clinical Characteristics for Families

This multiple congenital anomaly syndrome involves several systems of the body like central nervous system, face and eyes, skeleton and the genitourinary system.
During development of the baby within the womb of the mother, the formation of the brain and central nervous system occurs. If there is incomplete separation of the midline of the brain during development, it leads to morphologic brain abnormalities called holoprosencephaly which may also present as single nostril or a single median central incisor (mild form). Other structures of the brain like cerebellar vermis and corpus callosum may also be abnormally formed.

Microphthalmia/anophthalmia, a developmental defect of the eye where the eye is exceptionally small and may have anatomic abnormalities may also be seen in the affected individuals.

Females with normal internal and external genitalia may show abnormal sex chromosome composition. Normal female karyotype is 46, XX while in the females with this clinical entity, a karyotype of 46, XY may be seen.

The features affecting the skeleton may include short stature, abnormal bone of the thorax, ribs, vertebrae and clavicle, short fingers may also be noted in the affected individuals.