A case of testicular feminization with XYY karyotype

Giftedness and atypical sexual differentiation: enhanced perceptual functioning through estrogen deficiency instead of androgen excess

Syndromic autism spectrum conditions (ASC), such as Klinefelter syndrome, also manifest hypogonadism. Compared to the popular Extreme Male Brain theory, the Enhanced Perceptual Functioning model explains the connection between ASC, savant traits, and giftedness more seamlessly, and their co-emergence with atypical sexual differentiation. Overexcitability of primary sensory inputs generates a relative enhancement of local to global processing of stimuli, hindering the abstraction of communication signals, in contrast to the extraordinary local information processing skills in some individuals. Weaker inhibitory function through gamma-aminobutyric acid type A (GABAA) receptors and the atypicality of synapse formation lead to this difference, and the formation of unique neural circuits that process external information. Additionally, deficiency in monitoring inner sensory information leads to alexithymia (inability to distinguish one's own emotions), which can be caused by hypoactivity of estrogen and oxytocin in the interoceptive neural circuits, comprising the anterior insular and cingulate gyri. These areas are also part of the Salience Network, which switches between the Central Executive Network for external tasks and the Default Mode Network for self-referential mind wandering. Exploring the possibility that estrogen deficiency since early development interrupts GABA shift, causing sensory processing atypicality, it helps to evaluate the co-occurrence of ASC with attention deficit hyperactivity disorder, dyslexia, and schizophrenia based on phenotypic and physiological bases. It also provides clues for understanding the common underpinnings of these neurodevelopmental disorders and gifted populations.

Specific 5alpha-dihydrotestosterone binding in labial skin fibroblasts cultured from patients.with male pseudohermaphroditism

The cytoplasm of skin fibroblasts serially subcultured from the labium majus of normal human females binds 5alpha-dihydrotestosterone (5alpha-DHT) with high affinity and low capacity. Such binding was absent from the strains of two male pseudohermaphrodites with unambiguous female external genitalia: one of these was from a patient with the clinical features and a family history typical of complete testicular feminization; the other merited the same diagnosis on anatomic and endocrine grounds, but had an XYY karyotype in multiple tissues, including the testes. Normal cytoplasmic binding was found in strains from two prepubertal male pseudohermaphrodites with bilateral inguinal testes: one had unambiguous female external genitalia, the other had clitoromegaly; the former had normal specific nuclear binding of 5alpha-DHT, and thereby the target cell capacity for pubertal masculinization. Measurement of specific 5alpha-DHT binding by cultured labial skin fibroblasts should be an early step in the investigation of male pseudohermaphroditism with female external genitalia.