The phenotype of 45,X females: an anthropometric quantification

The Changing Face of Turner Syndrome

Turner syndrome (TS) is a condition in females missing the second sex chromosome (45,X) or parts thereof. It is considered a rare genetic condition and is associated with a wide range of clinical stigmata, such as short stature, ovarian dysgenesis, delayed puberty and infertility, congenital malformations, endocrine disorders, including a range of autoimmune conditions and type 2 diabetes, and neurocognitive deficits. Morbidity and mortality are clearly increased compared with the general population and the average age at diagnosis is quite delayed. During recent years it has become clear that a multidisciplinary approach is necessary toward the patient with TS. A number of clinical advances has been implemented, and these are reviewed. Our understanding of the genomic architecture of TS is advancing rapidly, and these latest developments are reviewed and discussed. Several candidate genes, genomic pathways and mechanisms, including an altered transcriptome and epigenome, are also presented.

Anthropometric variables as cardiovascular risk predictors in a cohort of adult subjects with Turner syndrome

BACKGROUND AND PURPOSE

Excessive adiposity is associated with cardiometabolic complications in Turner syndrome (TS) subjects. Reference data for predictive anthropometric indices of overweight/obesity and metabolic syndrome (MetS) are lacking for subjects with TS. The purpose of this study was to identify the best anthropometric predictor of cardiometabolic risk in a Latin-American cohort of TS subjects.

PATIENTS AND METHODS

This was a cross-sectional correlational study conducted in adult TS subjects (n=88) over the past seven years. Anthropometric parameters, body composition and biochemical variables were evaluated in a study and in a reference (n=57) group. Overweight/obesity and MetS were diagnosed using international consensus. The area under the ROC curve (AUC-ROC) was then used to determine the value of each anthropometric variable in predicting MetS or overweight/obesity.

RESULTS

The prevalence of MetS and overweight/obesity in TS subjects was 40% and 48%, respectively. All anthropometric and cardiometabolic variables were significantly increased in TS subjects when compared to the reference group, except for body mass index (BMI) and HDL-c. To detect MetS and overweight/obesity, waist to height ratio (WHtR) was found to have a higher correlation with cardiometabolic variables (TC, LDL-c, HDL-c levels and the LDL-c/HDL-c ratio), and to have a higher AUC-ROC and odds ratio than BMI, waist circumference (WC) and the waist to hip ratio (WHR).

CONCLUSION

The prevalence of MetS and overweight/obesity is elevated in TS subjects. WHtR was the most useful variable in predicting the presence of MetS and overweight and obesity in this TS cohort. A combination of WHtR with BMI or with WC could have the best clinical utility in identifying adult TS subjects with overweight/obesity and MetS, respectively.

Influence of long and short arms of X chromosome on maxillary molar crown morphology

Although genes on the human X chromosome reportedly influence tooth crown morphology, little is known about X chromosome activation or inactivation systems relevant to morphological variations. We assessed the relationships between tooth crown size and crown morphological traits in females with Turner syndrome, the variants of which include complete absence of one X chromosome, lack of the short arm (Xp), or duplication of the long arms (Xq), and then estimated the functions of Xp and Xq in the process of unilateral X chromosome inactivation during tooth crown development. The mesiodistal and buccolingual diameters in the maxillary first (M1) and second (M2) permanent molars were compared among X chromosome karyotypes by multiple regression analyses, and their relationships with the development of Carabelli’s cusp and the distolingual cusp were analyzed using logistic regression analysis.

The crown sizes increased in the order of the 46,X,i(Xq) karyotype, 45,X and 45,X/46,XX karyotypes, and control group. A lower frequency of Carabelli’s cusp and higher frequency of a reduced distolingual cusp in M1 were characteristics of Turner syndrome. The overall M1 and M2 crown sizes differed among the X chromosome karyotypes, whereas a smaller crown size was associated with a reduced distolingual cusp but not with Carabelli’s cusp. Considering the differences in chromosome arrangement among females with Turner syndrome and the process of unilateral X chromosome inactivation, the observed results can be considered in terms of quantity or number of promoters/inhibitors during tooth crown development.

The X chromosome karyotypes have a strong influence on the overall crown sizes of the M1 and M2 molars because those karyotypes with variable numbers of active gene regions directly influence tooth germ development in an early stage of human odontogenesis. The later forming cusps, such as the distolingual cusp and Carabelli’s cusp, may be affected by this developmental prerequisite.

Root lengths in the permanent teeth of 45,X females

OBJECTIVE

Studies in permanent and deciduous tooth crowns and permanent tooth roots in individuals with sex chromosome anomalies and in their relatives have given proof that the X chromosome affects enamel formation, root length and crown and root morphology. The present research studies the effects of sex chromosome deficiency on the development of permanent tooth root.

MATERIALS AND METHODS

This research investigated tooth root lengths in a group of 97 45,X females. As controls there were 32 sisters and 28 mothers of the 45,X females, 45 female and 42 male population controls and 15 45,X/46,XX females from the KVANTTI research project. Tooth root lengths on both sides of the jaws were measured from panoramic radiographs in each acceptable instance.

RESULTS

The results showed significantly shorter tooth root lengths in the 45,X females than in the female and male controls in all teeth measured, whereas in the female relatives tooth root lengths were shifted towards the aneuploids in relation to that in the general population. The tooth root lengths in the 45,X females differed more from those found in their sisters than in their mothers.

CONCLUSIONS

These results with the large pure sample size of the whole dentitions in patients with monosomy X confirm the earlier findings of short tooth roots in 45,X females. The fact that in most instances there were no significant differences in tooth root lengths between 45,X and 45,X/46,XX females comes close to the earlier findings regarding mesio-distal tooth crown sizes.

Effects of growth hormone on body proportions in Turner syndrome compared with non-treated patients and normal women

BACKGROUND

The majority of anthropometric assessments in Turner syndrome (TS) patients has focused on height.

AIM

To analyze body proportions in young adult TS patients either treated or not treated with rhGH, and to compare them with a group of age-matched healthy women.

SUBJECTS AND METHODS

Standing height, sitting height, weight, foot and leg lengths, arm span, head circumference, biliac and biacromial diameters were measured in 52 non-treated TS patients, 30 treated with rhGH and 133 healthy women.

RESULTS

Age at the start of rhGH therapy varied from 7.8 to 15.1 yr (10.0±1.3 yr), the duration of treatment from 2.8 to 8.2 yr (3.7±1.5 yr) and the mean recombinant human GH (rhGH) dose was 0.42 mg/kg/week (from 0.32 to 0.50 mg/kg/week). Nontreated patients did not show any difference in anthropometric variables when compared with the treated ones, except for hand length (p=0.02) and height (p=0.05), which were increased in the treated group. All anthropometric variables, except head circumference, were different when comparing TS patients (either treated or not) with age-matched healthy women.

CONCLUSION

Brazilian TS patients either treated or not with rhGH showed almost no differences in terms of their body proportions. This result is probably due to the late age at the start of treatment, and/or the short period of rhGH administration. Hand length was different between the groups, showing the importance of including the extremities in body proportion assessment during rhGH treatment of TS patients.

Protein metabolism in Turner syndrome and the impact of hormone replacement therapy

BACKGROUND

Studies have documented an altered body composition in Turner syndrome (TS). Body fat is increased and muscle mass is decreased. Ovarian failure necessitates substitution with female hormone replacement therapy (HRT), and HRT induces favourable changes in body composition. It is unknown how HRT affects protein metabolism.

AIM

To test whether alterations in body composition before and after HRT in TS are a result of altered protein metabolism.

DESIGN

We performed a randomized crossover study with active treatment (HRT in TS and oral contraceptives in controls) or no treatment.

MATERIALS AND METHODS

We studied eight women (age 29.7 +/- 5.6 (mean +/- SD) years) with TS, verified by karyotype, and eight age-matched controls (age 27.3 +/- 4.9 years). All subjects underwent a 3-h study in the postabsorptive state. Protein dynamics of the whole body and of the forearm muscles were measured by an amino acid tracer dilution technique using [(15)N]phenylalanine and [(2)H(4)]tyrosine. Substrate metabolism was examined by indirect calorimetry.

RESULTS

Energy expenditure was comparable among TS and controls, and did not change during active treatment. Whole-body phenylalanine and tyrosine fluxes were similar in the untreated situations, and did not change during active treatment. Amino acid degradation and protein synthesis were similar in all situations. Muscle protein breakdown was similar among groups, and was not affected by treatment. Muscle protein synthesis rate and forearm blood flow did not differ among groups or due to treatment.

CONCLUSION

Protein metabolism in TS is comparable to controls, and is not affected by HRT.

Turner syndrome in adulthood

Turner syndrome is a common genetic disorder associated with abnormalities of the X chromosome and occurs in about 50 per 100,000 liveborn girls. It is associated with reduced adult height, gonadal dysgenesis and thus insufficient circulating levels of female sex steroids and infertility. Morbidity and mortality are increased throughout the lifespan. The average intellectual performance is within the normal range. A number of recent clinical studies have given new insight particularly into the adult phase of Turner syndrome. Treatment with growth hormone during childhood and adolescence enables a considerable gain in adult height. In most cases puberty has to be induced and female sex hormone replacement therapy is given during adulthood. Type 2 diabetes is often seen, and hypertension and associated cardiovascular disorders are frequent. The proper treatments of these disorders have not been firmly established. Since the risk of cardiovascular and endocrinological disease is clearly elevated, proper care during adulthood is crucial. Cognition and social functioning are altered in Turner syndrome.

Proporções corporais em um grupo de pacientes brasileiras com Síndrome de Turner

OBJETIVO: Trata-se do primeiro estudo brasileiro com o objetivo de avaliar as proporções corporais de pacientes com síndrome de Turner (ST) não tratadas com hormônio de crescimento. MÉTODOS: Estudo transversal de 50 pacientes com ST (5 a 43 anos), avaliando-se idade, cariótipo, desenvolvimento puberal e medidas de estatura em pé e sentada, envergadura, peso, IMC, perímetro cefálico, mão e pé, perna, relação entre cintura e quadril, diâmetros biacromial e bi-ilíaco. Transformação dos dados em escore z de desvio-padrão. Realizada análise descritiva e aplicados o teste de Mann-Whitney e a análise de variância. RESULTADOS: Não foram observadas diferenças das variáveis em relação aos cariótipos: 22 eram impúberes e 28 púberes, e todas as variáveis em valores absolutos foram significativamente maiores na puberdade. Não foram observadas diferenças em relação aos escores z das variáveis analisadas em relação à puberdade. Todas as variáveis apresentaram escores z médios acima de -2, com exceção da estatura em pé e envergadura nas impúberes e também da estatura sentada e da mão nas púberes. O mesmo foi observado quando se analisou as 15 pacientes com idade > 20 anos, sendo apenas o peso, o IMC e os diâmetros biacromial e bi-ilíaco significativamente menores que os dados dinamarqueses de Gravholt e Naeera de 1997. CONCLUSÃO: O comprometimento de crescimento na ST ocorre fundamentalmente no eixo longitudinal, e os resultados observados neste estudo são comparáveis aos dinamarqueses.

Epidemiological, endocrine and metabolic features in Turner syndrome

Turner syndrome is one of the more common genetic disorders, associated with abnormalities of the X chromosome, and occurring in about 50 per 100,000 liveborn girls. Turner syndrome is usually associated with reduced adult height, gonadal dysgenesis, and thus insufficient circulating levels of female sex steroids, and infertility. A number of other signs and symptoms are seen more frequent with the syndrome. Morbidity and mortality is increased. The average intellectual performance is within the normal range. With respect to epidemiology, cardiology, endocrinology and metabolism a number of recent studies have allowed new insight. Treatment with GH during childhood and adolescence allows a considerable gain in adult height. Puberty has to be induced in most cases, and female sex hormone replacement therapy is given during adult years. The proper dose of HRT has not been established, and, likewise, benefits and/or drawbacks from HRT has not been thoroughly evaluated. Since the risk of cardiovascular and endocrinological disease is clearly elevated, proper care during adulthood is emphasized. In summary, Turner syndrome is a condition associated with a number of disease and conditions which are reviewed in present paper.

Relationship of deficits of FMR1 gene specific protein with physical phenotype of fragile X males and females in pedigrees: a new perspective

The effect of deficit of the FMR1-gene product (FMRP) on physical phenotype was investigated using a robust modification of the maximum likelihood estimators for pedigree data. The approach is a powerful method of examining genotype-phenotype relationships because it adjusts for intra-familial variation, and the robust modification allows violation of distributional assumptions in the data to be overcome by objectively down-weighting unusual observations. The data on 19 age- or height-adjusted physical measures including head, trunk and limb measures and height and weight from 110 extended fragile X families (including 185 fragile X males and females and 120 normal relatives) were related to the FMRP levels assessed in peripheral blood lymphocytes. A significant interaction between FMRP and age was also included in the models for some measures. The results have demonstrated a linear effect of progressively reducing levels of FMRP on the values of a majority of physical measures considered in the study. The most evident effect of FMRP deficit in sexes combined was in decreasing body height and limb length, and in increasing head height and the degree of connective tissue involvement (measured by the middle finger extension angle). Heritability estimated from the complex FMRP models showed the highest values for height and limb length, and the lowest for weight, finger extension angle and some facial measures. On the basis of the present data, a possible mechanism by which the FMRP deficit impacts physical phenotype is discussed.

Aspects of the treatment of Turner syndrome

Several issues have to be considered when taking care of girls and women with Turner syndrome. During childhood, short stature is the primary concern and treatment with growth hormone (GH) is now widely used, often in conjunction with the androgen, oxandrolone. Recent studies indicate that doses used previously in the treatment of short stature have been too small. Induction of puberty should be performed at an appropriate age with reference to the peers of the patient. In adulthood, female sex hormone substitution should be offered to possibly prevent the increased morbidity seen in Turner syndrome, which consists of increased risk of fractures and osteoporosis, a clustering of diseases like ischaemic heart disease, hypertension, stroke and Type 2 diabetes, the latter entities being involved in the insulin resistance syndrome. Furthermore, hypothyreosis are often seen and the risk of Type 1 diabetes may also be increased. Congenital malformations of the heart are frequently seen in Turner syndrome, possibly increasing the risk of dissecting aorta aneurism. Liver enzymes are often elevated in Turner syndrome and there may be an increased risk of cirrhosis of the liver. Mortality does seem to be increased in Turner syndrome and women with the 'pure' 45,X karyotype do seem to be most severely affected. In the clinical practice of Turner syndrome, a careful monitoring of glucose and bone metabolism, weight, thyroid function and blood pressure should be performed. A cardiovascular risk profile should be determined and the patient informed concerning risks and benefits from sex hormone replacement therapy. Based on the available literature, sex hormone replacement therapy is highly recommended, although at present there are no longitudinal data documenting the long-term positive effect of sex steroid substitution. However, hypogonadism is expected to explain at least part of the decreased lifespan found in Turner syndrome. Since general physicians encounter Turner patients infrequently, it is recommended that the care and treatment of Turner syndrome is centralised.

Orthodontic treatment for patients with Turner syndrome

The purpose of this study was to review the distinctive characteristics of Turner syndrome and to illustrate how they influenced the orthodontic treatment of a 17-year-old patient with Turner syndrome. The rate and the timing of growth, the development of the craniofacial structures, and the somatic and dental morphology unique to Turner syndrome significantly influence orthodontic treatment. Modifications that might be required to orthodontic treatment plans include (1) antibiotic prophylaxis, (2) occlusal adjustments to account for altered dental morphology, (3) altered treatment timing because of major differences in growth and differences between chronological and skeletal ages, and (4) growth hormone therapy. Orthodontists must understand the characteristics of Turner syndrome and modify the patient's treatment plan accordingly.

Reduced androgen levels in adult turner syndrome: influence of female sex steroids and growth hormone status

BACKGROUND AND OBJECTIVES

In girls with Turner syndrome androgen levels are reduced. In order to assess androgen status in women with Turner syndrome, we compared untreated adult women with Turner syndrome with a group of normal women. In addition, the effects of female sex hormone replacement therapy and GH status on the levels of circulating androgens in Turner syndrome was examined.

DESIGN

All patients were receiving female hormone replacement therapy (HRT), which was discontinued four months prior to the initial examination. Patients were studied before and during HRT. Following the initial evaluation, patients were given cyclical HRT for six months consisting of either oral substitution (17beta-oestradiol with norethisterone from day 13-22), or transdermal oestrogen substitution (17beta-oestradiol) with 1 mg norethisterone administered orally from day 13-22. Control subjects were studied once in the early follicular stage of the menstrual cycle.

SUBJECTS

The study group consisted of 27 (33.2 +/- 7.9 years) patients with Turner syndrome and an age matched control group of 24 (32.7 +/- 7.6 years) normal women.

MEASUREMENTS

Body composition measures, SHBG, testosterone (T), free testosterone (FT), dihydrotestosterone (DHT), alpha-4-androstendione (A), dehydroepiandrosterone sulphate (DHEAS), 17beta-oestradiol (E2), oestrone (E1), oestrone sulphate (ES), 24 h integrated GH concentration (ICGH), insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein (IGFBP-3) were determined at baseline and after six months in women with Turner syndrome, and at baseline in control women.

RESULTS

Circulating levels of A, T, FT, DHT, and SHBG were reduced by 25-40% in comparison with age matched normal women. The level of DHEAS was normal. The level of E2 was undetectable and levels of E1 and ES were very low in untreated Turner women. Treatment with 17beta-oestradiol and norethisterone increased oestrogen to levels comparable to those of normal women, while further decreasing FT (P = 0.02), DHT (P = 0.04), and T (P = 0.1). In untreated women with Turner syndrome IGF-I correlated significantly with DHEAS (R = 0.503, P < 0.01), while in normal women IGF-I correlated with A (R = 0.637, P < 0.01), T (R = 0.536, P < 0.01), and FT (R = 0.700, P < 0.01). During hormonal replacement in women with Turner syndrome IGF-I correlated significantly with DHEAS (R = 0.547, P < 0.01). Employing multiple regression analysis IGFBP-3, ICGH, DHEAS and fat free mass explained 85% (adjusted R = 0.92, P < 0.0005) of the variation in the level of IGF-I in untreated Turner syndrome. In treated Turners IGFBP-3, ICGH, SHBG, T, and FT explained 78% (adjusted R = 0.88, P < 0.0005). In controls IGFBP-3, SHBG, BMI and age explained 74% (adjusted R = 0.86, P < 0.0005) of the variation in IGF-I, while GH status did not contribute at all.

CONCLUSION

The present study shows that many adults with Turner syndrome have reduced levels of circulating androgens, compared with an age-matched group of normal women. Conditions associated with Turner syndrome such as increased prevalence of sexual problems, reduced bone mineral content, osteoporosis, and an increased incidence of fractures and alterations in body composition could perhaps be alleviated or abolished by substitution with a low dose of androgens. Treatment with female hormonal replacement therapy is associated with a decrease in testosterone, free testosterone and dihydrotestosterone, possibly mediated by the androgenic effect of norethisterone. Furthermore significant differences in sex steroid levels, GH status and indices of body composition can be compatible with comparable levels of IGF-I in two very different groups of individuals.

Reference values for body proportions and body composition in adult women with Ullrich-Turner syndrome

This cross sectional study was undertaken to establish reference values for adult women with Ullrich-Turner syndrome (UTS) verified cytogenetically by blood karyotyping and not treated with growth hormone during childhood and adolescence, with respect to anthropometric and body composition measurements, for future evaluations of growth promoting therapy. All members of the Danish Turner Association were invited, and 79 women with UTS participated. Forty-two had the 45,X karyotype and the other 37 had different karyotypes. Outcome measures were height, sitting height, arm span, length of hand and foot, biacromial and biiliac diameter, and hip, waist, and head circumference. Bioelectrical impedance was performed, and total body water, lean body mass, and fat mass were calculated. Results give a very distinct anthropometric picture of adult women with the UTS, with a mean height of 146.8+/-6.7 cm (mean+/-SD), sitting height of 78.6+/-3.6 cm, arm span measurements of 147.9+/-7.1 cm, being between 3 and 4 standard deviation scores (SDS) below average; with a mean hand length of 17.0+/-1.1 cm and foot length of 22.4+/-1.2 cm, being around 1.5 SDS below average; a mean weight of 56.3+/-12.8 kg, head circumference of 55.3+/-2.0 cm and biacromial diameter of 36.5+/-2.0 cm, being around 0 SDS; and finally, biiliacal diameter of 29.5+/-2.2 cm, being 1.4 SDS above average. The average body mass index (BMI) in the study was 26.3+/-5.3 kg/m2. As a group, females with UTS are overweight when compared with a group of "normal" women, with a higher fat mass, a lower lean body mass, but with a comparable amount of total body water (in %). This study presents the first comprehensive reference data on body proportions in the adult UTS. It shows that adult women with the Ullrich-Turner syndrome has a characteristic anthropometric shape. The data should be of use for future evaluations of growth hormone treatment or other growth promoting therapy in the UTS on anthropometric and body composition variables.

Torus mandibularis in 45,X females (Turner syndrome)

Ninety-three Finnish females with a 45,X chromosome constitution, 78 first-degree female, and 37 first-degree male relatives were examined to determine the frequency and expression of torus mandibularis. The results indicate that among adults the frequency of the trait was significantly lower and the expression weaker in the 45,X females than in male control relatives. A similar trend was observed in comparison to normal females. In juveniles the trend was reversed. Our findings suggest that the sex chromosomes may have an influence on the occurrence, expression, and timing of development of the mandibular torus. Sexual dimorphism in the manifestation of torus mandibularis may result particularly from the effect of the Y chromosome on growth.

Recognizing Ullrich-Turner syndrome by discriminant analysis of craniofacial structure

In the present paper, we propose an efficient strategy for identification of craniofacial anomalies in the Ullrich-Turner syndrome (UTS). Standardized portrait- and profile-photographs were taken of 21 UTS patients with X-monosomy and 21 normal females. Twenty-seven craniofacial parameters were read from the photographs. The data were analyzed by discriminant analysis, a multivariate statistical method. The result was a function represented by a linear combination of all those craniofacial parameters which best separate the two groups. The discriminant function was applied to 15 additional patients with UTS of various cytogenetic types. All 15 patients were classified correctly. The technique facilitates syndrome-recognition and is a contribution toward the study of karyotype-phenotype relations.

Head circumference and IQ of children with sex chromosome abnormalities

At all ages XXX girls had significantly smaller head circumferences than control girls. Their IQ deficit was 24 points and IQ at age seven correlated significantly with head circumference at birth. In XXY boys, head circumference was significantly reduced at birth and up to nine years of age. The XXY boys' IQ deficit was 22 points, but IQ did not correlate with head circumference, as reductions in the two parameters did not always occur in tandem. The ratio of height-to-head circumference differed most in this group and could be useful in clinical recognition of this condition. XYY boys' head size did not differ from controls, despite their greater height, lower IQ scores indicating an adverse effect of an additional Y chromosome on brain development. The major factor affecting IQ outcome in the cohort was abnormal karyotype, with smaller effects from social class and head growth.

Body proportions in individuals with Turner syndrome. The Dutch Growth Hormone Working Group

The body proportions in 191 individuals with Turner syndrome (TS) were investigated. At 3 years of age the mean sitting height in TS was normal, thereafter trunk growth was impaired, resulting in a standard deviation score (SDS) of -2.4 in the adult. From 3 to 12 years of age the mean SDS of leg length increased from -2.7 to -3.6; and then fell to -2.5. At 3 years of age the ratio of sitting height to leg length was 3.2 standard deviations (SD) above the normal mean. Thereafter the ratio slowly approached the normal percentiles. It was +0.6 SD in 15- to 18-year-old women. Thereafter it increased to 1.7 for adults with TS. Knemometric measurements in 32 individuals with TS and 32 controls revealed that in TS the upper legs were relatively shorter than the lower legs. We conclude that children with TS, and to a lesser extent adults, have a disproportionately short stature with relatively short legs whereas body proportions are almost normal in adolescents.

Palatal and mandibular arch morphology in 47,XYY men and in other sex-chromosome anomalies

Dimensions of the maxilla and mandible were studied in 47,XYY men and their first-degree male relatives, and the results compared with similar studies of other sex-chromosome anomalies. An extra Y chromosome in 47,XYY men caused an increase in palatal growth transversely and anteroposteriorly and in mandibular arch length anteroposteriorly compared to normal men. Palatal height and mandibular width were smaller with this chromosome pattern. Increase in the number of sex chromosomes is associated with changes in palatal and mandibular arch dimensions, more often an increase than a decrease. The findings support earlier observations that the palate becomes shallower with the addition of an X chromosome. It is also apparent that the influence of X and Y chromosomes differs, at least regarding the magnitude of metric changes.

Comparative cephalometric analysis in patients with X-chromosome aneuploidy

The influence of abnormal sex-chromosome constitution on cranial growth, shape and position of the craniofacial structures was analysed. Reduced cranial growth was found in women with Turner's syndrome (45 XO chromosome constitution) and in men with Klinefelter's syndrome (47 XXY chromosome constitution). Lack of or an extra X chromosome produced opposite effects on cranial-base flexion, jaw displacement and maxillary and mandibular inclination to the anterior cranial base. An extra X chromosome affected deviation in sagittal jaw relation while lack of an X chromosome influenced mandibular shape.

A study in 47,XYY men of the expression of sex-chromosome anomalies in dental occlusion

Occlusal traits were determined for 47,XYY men and compared with previous determinations of occlusal morphology in other sex-chromosome anomalies and in normal women and men. The 47,XYY men, like 47,XXY men, tended to have a mesial molar occlusion and a mandibular overjet more often than did other groups, while 45,X women (Turner patients) clearly had the highest frequency of distal occlusion and large overjet. The 47,XXY men had the highest frequency of most occlusal anomalies. As a whole, these and earlier findings suggest that the number of X or Y chromosomes is associated negatively with distal occlusion and lateral crossbite, whereas a positive association was found with mesial molar occlusion and scissors bite.

Skeletal maturity, dental maturity, and eruption in young patients with Turner syndrome

A major problem for patients with Turner syndrome is their small body height. The rapid biotechnologic development has now made treatment with growth hormone possible at a larger scale. The aim of this investigation was to evaluate skeletal maturity, dental maturity, and eruption in a group of young patients before hormone therapy. The material comprised 33 patients aged 7-16.7 years. The skeletal maturity, as judged from hand radiographs, was on an average 2.3 years retarded (p < 0.001) and showed increasing retardation with increasing age. The dental maturity, assessed from the formation stages of the permanent teeth on panoramic radiographs, was accelerated, with a mean value of 1 year (p < 0.001). The timing of clinical eruption did not differ significantly from that of our reference material; the Turner girls were on an average 3.7 months ahead. Several patients had local eruption problems, especially in the maxillary lateral segments. It is suggested that disharmony between tooth size and arch size may contribute to this problem.

Multivariate analysis of body shape in fragile X (Martin-Bell) syndrome

Human body shape measures can be more informative in studies of developmental abnormalities than distances between body landmarks. Such measures were obtained by an appropriate transformation of 34 distances between trunk/limbs and head/face landmarks in 43 men and 72 women with the Martin-Bell Syndrome (MBS), and in 99 and 103 normal men and women, respectively. The transformation of the original distances was performed by adjusting individual measures for an overall size measure using regression analysis. Thus obtained body shape variables were used in discriminant analysis in order to obtain unbiased classification probabilities of individuals having the MBS or being normal. The average percent correctly classified male and female individuals was high (93 and 87, respectively). Moreover, the body shape variables were used to obtain shape dimensions by means of principal component analysis. There was no difference between the MBS and normal individuals in the first (most important) principal component (shape dimension). This component represents the relative proportions between trunk and limb lengths and widths, or between midfacial lengths and widths. However, there were appreciable differences in some succeeding components. The problem of interpretation of shape dimensions as derived from principal component analysis and of their relevance to abnormal development in the MBS individuals is discussed.

Anthropometry in Martin-Bell syndrome

Thirty anthropometric measurements were analyzed in 147 adults with Martin-Bell syndrome (MBS) (56 men and 91 women) and in a random sample of 108 normal women and 111 men. Results of the univariate comparison of the age, height, or weight-adjusted variables between MBS and normal individuals of either sex indicated that a decrease in stature, in upper limb length, and in upper face height, and an increase in jaw length, chest circumference, and waist width occurred in both affected men and in heterozygous women. While the increase in ear height and breadth and in hypermobility of finger joints and decrease in palm width and bigonial diameter occurred only in affected men, increased bispinal and bitrochanteric diameters, upper arm circumference, and palm and wrist widths were characteristic deviations in heterozygous women. Multivariate analysis in the form of principal components showed some differences in the pattern of interrelationships in individual measures between MBS and normal individuals. In particular, and in contrast with both normal groups, height and weight tended to load on separate components (as did head and midfacial measures) in MBS individuals. A discriminant function based on all body measurements included in this study resulted in almost complete separation of discriminant scores of normal from those of MBS men and in good separation of the scores from normal and heterozygous women. Classification rates based on these functions were from 95% in men to 85% in women. These already high classification rates may be further improved mainly by enlarging the samples and including some other category of traits such as dermatoglyphic measurements.

Size of the alveolar arch of the mandible in relation to that of the maxilla in 45,X females

Length and width of the alveolar arch of the mandible and maxilla were determined from hard stone casts of 45,X females (Turner syndrome), female first-degree relatives, and population control females. Adjusted mean values (covariance adjusted for age, previous orthodontic treatment, and number of lost permanent teeth) for mandibular arch width were larger in 45,X females than in normal controls, both absolutely and, more clearly, in relation to the maxillary arch. The total absolute length of the mandibular arch was slightly reduced in 45,X females. The broader and shorter alveolar arch of the mandible in relation to the narrower but normal-length maxillary arch reflects imbalanced facial growth in subjects with one X-chromosome instead of the normal two.

Clinical anthropometry and medical genetics: a compilation of body measurements in genetic and congenital disorders

Anthropometry has become an important tool in the study of genetic conditions, particularly as a diagnostic aid for the clinical geneticist. However, many practicing physicians do not do anthropometry of patients for several reasons, such as: appropriate measurements in a given situation are unknown; normative reference data are unavailable; or analysis and interpretation of the data are confusing. In this review we present an annotated compilation of informative measurements for hereditary and congenital disorders and a guide to normative anthropometric data of use in evaluation and diagnosis of such disorders. Further development of multivariate approaches will enhance the application of anthropometry as a means of identifying and classifying a syndrome and documenting the natural history of many disorders. Continued cooperation among physicians, geneticists, and anthropologists for the collection and assessment of patient and normative data is essential if these goals are to be realized.

Minute chromosomes replacing the Y chromosome carry Y-specific sequences by restriction fragment analysis and in situ hybridization

Two unrelated males, a 43-year-old man with azoospermia and a 4-year-old boy with stature at the 10th centile, had similar karyotypes: 46,X,min. The minutes, present in all cells analyzed, stained weakly with G-, C-, and Q-banding methods. To elucidate their origin we used molecular techniques: In HaeIII digests of total genomic DNA from both individuals, no Y-specific reiterated sequences were detected. However, restriction fragment analysis with probe pDP31 demonstrated that the patients' DNA contained the Y-specific fragment. In situ hybridization with the same probe showed that these sequences were present on the minute chromosomes and have not been translocated elsewhere.

An anthropometric assessment of Huntington's disease patients and families

An anthropometric investigation was designed to evaluate patterns of physical deterioration in Huntington's disease (HD). In this study a comprehensive set of measurements was taken including height, weight, body circumferences, skinfold thickness, and craniofacial, linear, and breadth components of the body, on 44 normal, 26 affected, and 70 at-risk individuals between 14 and 88 years of age. The anthropometric data were converted to z-scores using standards to adjust for age and sex differences. These scores were then adjusted for inter-family variation. There were significant differences among normal and affected individuals for all dimensions of body mass, as well as for several craniofacial and linear components of the body. Several significant differences were also found between normals and particular age cohorts of at-risk persons. HD gene carrier status was further assessed by factor analysis of the adjusted scores.

Effects of X chromosome on size and shape of body: An anthropometric investigation in 47,XXY males

The effects of an extra X chromosome on size and shape of body and head were studied in 47,XXY males; 25 anthropometric measurements were recorded from 29 adult 47,XXY males and compared with those of male relatives and control males. In stature, arm length, leg length, triceps skinfold, and subscapular skinfold 47,XXY males were larger and in biacromial diameter, bideltoid breadth, wrist breadth, and in most head dimensions smaller than normal males. Arm length was increased less than leg length. Increase in stature seemed to be caused solely by increased leg length, and the somewhat feminine proportions in trunk were caused by decrease in biacromial diameter. Correlations of the body and head dimensions between 47,XXY males and their male relatives were found to be normal. The present findings support the earlier proposals that X chromosome carries genes which influence linear growth. It is suggested that the reduction in biacromial diameter is caused by lowered plasma testosterone level which may also have affected sitting height. The control of body and head dimensions seems to be maintained relatively normal.