Terminal osseous dysplasia

Terminal osseous dysplasia is a disorder primarily involving skeletal abnormalities and certain skin changes. It is a member of a group of related conditions called otopalatodigital spectrum disorders, which also includes otopalatodigital syndrome type 1, otopalatodigital syndrome type 2, frontometaphyseal dysplasia, and Melnick-Needles syndrome. In general, these disorders involve hearing loss caused by malformations in tiny bones in the ears (ossicles), problems in the development of the roof of the mouth (palate), and skeletal abnormalities involving the fingers or toes (digits), although not every condition in the spectrum has all of these features.

Terminal osseous dysplasia occurs only in females; males with the condition do not survive to birth. The skeletal abnormalities in people with this condition typically include permanently bent fingers and toes (camptodactyly) and underdevelopment (hypoplasia), shortening, or fusion of the bones in the wrists and hands. The outer layer of bone (cortex) in other parts of the skeleton may be abnormal, and some affected individuals have bowed arms or legs or are shorter than their peers.

Skin abnormalities are also common in terminal osseous dysplasia. Many individuals with the condition have dark patches of skin on their face, often near the temples. In addition, affected infants commonly develop noncancerous (benign) tumors called fibromas on their fingers or toes. The tumors may reappear after being removed, but they tend to go away and stop reoccurring in childhood.

Other signs and symptoms can occur in people with terminal osseous dysplasia, including extra oral frenulae, which are the thin pieces of tissue in the mouth that connect the inside of the lips to the gums; widely spaced eyes; and hair loss. Some people with this condition have an abnormality in the muscular wall (septum) that separates the right and left sides of the heart (cardiac septal defect).