ABSTRACT
Rabson-Mendenhall syndrome is characterized by growth retardation, dysmorphisms, lack of subcutaneous fat, acanthosis nigricans, enlarged genitalia, hirsutism, premature and dysplastic dentition, coarse facial features, paradoxical fasting hypoglycemia and post-prandial hyperglycemia, extreme hyperinsulinemia and pineal hyperplasia. We describe a six-month-old female child with physical features suggestive of the Rabson-Mendenhall syndrome. The child also had medullary nephrocalcinosis.
Subject(s)
Abnormalities, Multiple/genetics , Acanthosis Nigricans/genetics , Consanguinity , Diabetes Mellitus/blood , Diabetic Ketoacidosis/genetics , Failure to Thrive , Female , Growth Disorders/genetics , Hirsutism/genetics , Humans , Infant , Insulin Resistance/genetics , Odontodysplasia/genetics , SyndromeABSTRACT
The association or interaction of histocompatibility antigens (HLA) and acanthosis nigricans with type A insulin resistance was studied in 13 patients (10 from family I, 2 from family II and an isolated case) for both sexes. HLA typing for the A, B, C and D antigens was performed by a standard microcytotoxicity test for all patients and for 100 normal controls from the same geographic area. The frequency of HLA B8 was 21% in the control group and 100% in patients with acanthosis nigricans. The frequency of HLA A1B8 was 15% in controls and 73% n acanthotic patients. All the members of family I presenting the association of a possibile insulin receptor defect (most likely provided by patient 2) with HLA B8 (provided by patient I) showed a more pronunced clinical and laboratory expression of insulin resistance. These data suggest that class I antigens of major histocompatibility complex (MHC), A1 and/or B8, may be involved in the pathogenesis of some forms of insulin resistance such as acanthosis nigricans (type A syndrome), possibly by a molecular interaction of the antigens with insulin receptors
Subject(s)
Humans , Child , Adolescent , Adult , Middle Aged , Male , Female , Acanthosis Nigricans/genetics , HLA Antigens/genetics , Insulin Resistance/genetics , Acanthosis Nigricans/complications , Blood Glucose/analysis , Glucose Tolerance Test , Insulin Resistance/complications , PedigreeABSTRACT
This study was designed to determine the forearm exchange of glucose and potassium in four members of a family exhiting acanthosis nigricans and insulin resistance. Total areas under the curves for potassium release or uptake were within the normal range in all patients. Peripheral glucose uptake, however, was normal in 3 patients and lower in one patiente. In the latter patient, the dissociation observed between glucose and potassium transport suggests several manners of differential impairment of insulin action and/or steps distal to the insulin receptor as being responsible for insulin resistance