A disorder due to thyroid dyshormonogenesis, causing large goiters of elastic and soft consistency in the majority of patients. Although the degree of thyroid dysfunction varies considerably among patients with defective thyroglobulin synthesis, patients usually have a relatively high serum free triiodothyronine (T3) concentration with disproportionately low free tetraiodothyronine (T4) level. The maintenance of relatively high free T3 levels prevents profound tissue hypothyroidism except in brain and pituitary, which are dependent on T4 supply, resulting in neurologic and intellectual defects in some cases.
An autosomal recessive condition associated with a distinctive retinal appearance and no apparent visual or electrophysiologic deficits. Affected individuals are asymptomatic, but fundus examination reveals a striking pattern of diffuse, yellow-white, fleck-like lesions extending to the far periphery of the retina but sparing the foveal region.
A form of Dowling-Degos disease, a genodermatosis manifesting with postpubertal reticulate hyperpigmentation that is progressive and disfiguring, and small hyperkeratotic dark brown papules that affect mainly the flexures and great skin folds. Patients usually show no abnormalities of the hair or nails. DDD4 is characterized by prominent involvement of non-flexural skin areas.
A rare form of diabetes distinct from childhood-onset autoimmune diabetes mellitus type 1. It is characterized by insulin-requiring hyperglycemia that is diagnosed within the first months of life. Permanent neonatal diabetes requires lifelong therapy.