Anthropometric comparison of mentally retarded males with and without the fragile X syndrome

Abstract

An anthropometric survey of 41 variables (weight, height, 10 linear, 4 breadth, 22 craniofacial, 2 skinfold, and testicular volume), including multivariate discriminant analysis, was undertaken on 110 mentally retarded males (39 with and 71 without the fra(X) syndrome). The mean Z scores of the fra(X) syndrome males fell between −2.00 and 8.38 for bizygomatic diameter and testicular volume, respectively, and the range of the mean Z scores of the non-fra(X) males was from −2.64 to 2.26 for hand breadth and testicular volume, respectively. There was a statistically significant difference (P < .05) between fra(X) and non-fra(X) males for 18 measurements (weight, height, 7 linear, 2 breadth, 5 craniofacial, 1 skinfold, and testicular volume), with the greater measurements (excluding bizygomatic diameter) found in fra(X) males. Sitting height, knee-buttock length, middle finger length, and hand length were negatively correlated (P < .05) with age, whereas bizygomatic diameter, ear length, and ear width were positively correlated (P < .05) with age and head circumference, head length, and outer canthal distance were positively correlated (P < .05) with fra(X) chromosome expression in the fra(X) males. Triceps and subscapular skinfold thicknesses were negatively correlated (P < .05) with age, whereas ankle breadth, ear length, ear width, and nose length were positively correlated (P < .05) in the non-fra(X) males. Discriminant analysis of 34 fra(X) and 71 non-fra(X) males resulted in a discriminant function based on 6 of 17 anthropometric variables and age. In the discriminant analysis, patients with the fra(X) syndrome were distinguished from mentally retarded males without the fra(X) syndrome at an overall correct classification rate of 97.1% in our sample. The 6 anthropometric variables in the discriminant function were the Z scores representing testicular volume, ear width, head breadth, bizygomatic diameter, hand breadth, and hand length. Additional research is needed to test the usefulness of these variables in screening mentally retarded males for the fra(X) syndrome.

Anthropometric and craniofacial patterns in mentally retarded males with emphasis on the fragile X syndrome

“…A cytogenetic and clinical survey of 236 mentally retarded males (39 with and 197 without the fra(X) syndrome or other recognizable cause of their retardation) was undertaken recently including a comprehensive assessment of anthropometric variables, and significant differences were reported for 18 measurements (weight, height, 7 linear, 2 breadth, 5 craniofacial, 1 skinfold and testicular volume) (Butler et al 1991a, Butler & Singh 1993 …”

“…Hagerman et al (1988) reported finding positive fragile X chromosome results in 50% of mentally retarded males who were examined and found to have large ears, macroorchidims, and hand callouses. Recently, Butler et al (1991aButler et al ( , 1991b and Hagerman et al (1991) reported that certain physical characteristics (e.g., ear width, testicular volume, bizygomatic diameter, head breadth, plantar crease, hyperflexibility) could be used to identify more than 90% of mentally retarded males with the fra(X) syndrome. Butler et al (1992) also reported anthropometric standards for clinical use for weight, height, head circumference, ear length and testicular volume for fra(X) syndrome males.…”

“…Our research illustrates the use of anthropometry in identifying differences between mentally retarded males with or without the fra(X) syndrome and offers a comprehensive approach for screening males for the fra(X) syndrome and selecting those individuals for cytogenetic and/or molecular genetic testing. 1983, Meaney & Farrer 1986, Meaney & Butler 1989, Butler et al 1991a. One of these conditions is the fragile X (fra(X)) or Martin-Bell syndrome, the most common familial cause of mental retardation.…”

“…anthropometry; fragile X chromosome expression; pattern profiles Anthropometric methods have been applied increasingly in the clinical evaluation and diagnosis of individuals with genetic disorders and other health problems (Dequeker et al 1983, Meaney & Farrer 1986, Meaney & Butler 1989, Butler et al 1991a. One of these conditions is the fragile X (fra(X)) or Martin-Bell syndrome, the most common familial cause of mental retardation.…”

Fragile X syndrome: clinical and cytogenetic studies

“…This study found a higher incidence of narrow inner canthal distance (100% v 88%). The narrow inner canthal distance associated with normal outer canthal distance is related to the long palpebral fissures observed in anthropometric studies 1,12 . Fifty percent of adult males have long ears and 30% prominent ears 8 .…”