The use of testicular volume as a clinical marker for cytogenetic disorders in mentally retarded males

Abstract

ABSTRACT. The testicular volumes (V) of 817 adult (non‐Down's syndrome) institutionalized males were calculated. The mean testicular volume was 19.5±15.8 ml, comparable to the normal adult male mean of 17–19 ml. However, the number of institutionalized males with V≤25 ml and V≤10 ml was increased approximately fourfold over the normal male population. Resident adult males were grouped into three categories based on their testicular volumes: (1) V≤25 ml (macro‐orchid); (2) V≤15 ml (micro‐orchid); and (3) 15 < V < 25 ml (‘normal’). An equal number of randomly selected males from each category were cytogenetically screened for the fra(X) syndrome as well as for non‐fra(X) chromosome abnormalities. The overall frequencies of these disorders were 3.1% and 3.9%, respectively. The fra(X) syndrome was found in a significantly higher percentage of macro‐orchid males (10.3%) as compared to males with either micro‐orchidism (1.2%) or normal testicular volume (1.2%). There was no significant difference in the distribution of either fra(X) negative non‐specific XLMR or non‐fra(X) chromosome abnormalities among resident males from these three categories. Testicular volumes ≥25 ml, especially those exceeding 40 ml, were thus shown to be useful clinical markers in the diagnosis of the fra(X) syndrome. Reduced testicular volume was not a useful clinical marker in the evaluation of other non‐Down's syndrome chromosome abnormalities.

Evaluation of clinical checklists for fragile X syndrome screening in Brazilian intellectually disabled males

“…Large testes have been reported as common in males with FXS. According to some authors, this feature is more evident after puberty, being difficult to screen in younger boys (Giangreco et al, 1996;Hagerman et al 1991;Hjalgrim et al, 1998;Kirkilionis et al, 1988). Another trait that becomes more evident postpubertally is the long face (Hagerman, 1987;Thake et al, 1985).…”