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- What is Rabson–Mendenhall syndrome?
Rabson–Mendenhall syndrome is a disorder characterized by severe insulin
resistance and manifests as characteristics facies (prominent widely spaced
eyes, broad nose, and large, low-set ears), growth retardation, severe acanthosis
nigricans, protuberant abdomen, thick nails, early dentition with crowding of
teeth, features of androgen excess (hirsutism, clitoromegaly in girls and macro-
penis in boys), pineal hyperplasia, and fasting hypoglycemia and postprandial
hyperglycemia. The disorder is intermediate in severity between Donohue syn-
drome and type A insulin resistance. It is inherited as an autosomal recessive
trait and is due to homozygous mutations in insulin receptor gene. Insulin,
insulin sensitizers, and IGF1 has been used with limited success. These chil-
dren usually survive till second decade of life.- When to suspect mitochondrial diabetes?
Mitochondrial diabetes should be suspected in a young individual with diabetes
(onset before 30 years) and sensorineural deafness. In addition, the family his-
tory of matrilinear transmission of diabetes should also raise a suspicion of
mitochondrial diabetes. Matrilinear transmission refers to pattern of inheritance
wherein a female transmits the disease to all her children, while the affected
males fail to transmit the disease (as sperm sheds the mitochondria beforeabFig 12.9 (a) Typical elfin facies, severe and diffuse acanthosis nigricans in an infant with lepre-
chaunism, (b) clitoromegaly in the same patient as a manifestation of hyperinsulinemia-mediated
androgen excess
12 Diabetes in the Young