Assessment of aortic dilatation in Chinese children and adolescents with Turner syndrome: a single center experience.

BACKGROUND: Patients with Turner syndrome (TS) face an increased risk of developing aortic dilatation (AD), but diagnosing AD in children presents greater complexity compared to adults. This study aimed to investigate the application of various assessment indicators of AD in Chinese children and adolescents with TS. METHODS: This study included TS patients admitted to Shenzhen Children's Hospital from 2017 to 2022. Cardiovascular lesions were diagnosed by experienced radiologists. Patients without structural heart disease were divided into different body surface area groups, then the Chinese TS population Z-score (CHTSZ-score) of the ascending aorta was calculated and compared with other indicators such as aortic size index (ASI), ratio of the ascending to descending aortic diameter (A/D ratio), and TSZ-score (Quezada's method). RESULTS: A total of 115 TS patients were included, with an average age of 10.0 ± 3.7 years. The incidences of the three most serious cardiovascular complications were 9.6% (AD), 10.4% (coarctation of the aorta, CoA), and 7.0% (bicuspid aortic valve, BAV), respectively. The proportion of developing AD in TS patients aged ≥ 10 years was higher than that in those < 10 years old (16.6% vs. 1.8%, P = 0.009), and the proportion of patients with CoA or BAV who additionally exhibited AD was higher than those without these conditions (31.6% vs. 5.2%, P < 0.001). The ASI, A/D ratio, TSZ-score, and CHTSZ-score of the 11 patients with AD were 2.27 ± 0.40 cm/m2, 1.90 ± 0.37, 1.28 ± 1.08, and 3.07 ± 2.20, respectively. Among the AD patients, only 3 cases had a TSZ-score ≥ 2, and 2 cases had a TSZ-score ≥ 1. However, based on the assessment using the CHTSZ-score, 6 patients scored ≥ 2, and 5 patients scored ≥ 1. In contrast, the TSZ-score generally underestimated the aortic Z-scores in Chinese children with TS compared to the CHTSZ-score. CONCLUSIONS: The applicability of ASI and A/D ratio to children with TS is questionable, and racial differences can affect the assessment of TSZ-score in the Chinese population. Therefore, establishing the CHTSZ-score specifically tailored for Chinese children and adolescents is of paramount importance.

Assessment of obstetric characteristics and outcomes associated with pregnancy with Turner syndrome.

OBJECTIVE: To assess national-level trends, characteristics, and outcomes of pregnancies with Turner syndrome in the United States. DESIGN: Cross-sectional study. SETTING: The Healthcare Cost and Utilization Project's National Inpatient Sample. SUBJECTS: A total of 17,865,495 hospital deliveries from 2016-2020. EXPOSURE: A diagnosis of Turner syndrome, identified according to the World Health Organization's International Classification of Disease 10th revision code of Q96. MAIN OUTCOME MEASURES: Obstetrics outcomes related to Turner syndrome, assessed with inverse probability of treatment weighting cohort and multivariable binary logistic regression modeling. RESULTS: The prevalence of pregnant patients with Turner syndrome was 7.0 per 100,000 deliveries (one in 14,235). The number of hospital deliveries with patients who have a diagnosis of Turner syndrome increased from 5.0 to 11.7 per 100,000 deliveries during the study period (adjusted-odds ratio [aOR] for 2020 vs. 2016; 2.18, 95% confidence interval [CI] 1.83-2.60). Pregnant patients with Turner syndrome were more likely to have a diagnosis of pregestational hypertension (4.8% vs. 2.8%; aOR 1.65; 95% CI 1.26-2.15), uterine anomaly (1.6% vs. 0.4%; aOR, 3.01; 95% CI 1.93-4.69), and prior pregnancy losses (1.6% vs. 0.3%; aOR 4.70; 95% CI 3.01-7.32) compared with those without Turner syndrome. For the index obstetric characteristics, Turner syndrome was associated with an increased risk of intrauterine fetal demise (10.9% vs. 0.7%; aOR 8.40; 95% CI 5.30-13.30), intrauterine growth restriction (8.5% vs. 3.5%; aOR 2.11; 95% CI 1.48-2.99), and placenta accreta spectrum (aOR 3.63; 95% CI 1.20-10.97). For delivery outcome, pregnant patients with Turner syndrome were more likely to undergo cesarean delivery (41.6% vs. 32.3%; aOR 1.53; 95% CI 1.26-1.87). Moreover, the odds of periviable delivery (22-25 weeks: 6.1% vs. 0.4%; aOR 5.88; 95% CI 3.47-9.98) and previable delivery (<22 weeks: 3.3% vs. 0.3%; aOR 2.87; 95% CI 1.45-5.69) were increased compared with those without Turner syndrome. CONCLUSIONS: The results of contemporaneous, nationwide assessment in the United States suggest that although pregnancy with Turner syndrome is uncommon this may represent a high-risk group, particularly for intrauterine fetal demise and periviable delivery. Establishing a society-based approach for preconception counseling and antenatal follow-up would be clinically compelling.

Risk assessment for aortic dissection in Turner syndrome: The role of the aortic growth rate.

OBJECTIVE: The risk of aortic dissection (AoD) is increased in Turner syndrome (TS) but predicting those at risk is difficult. Based on scarce evidence, preventive aortic surgery is recommended when aortic diameter increases >5 mm/year. To investigate the aortic growth rate in TS and TS-related conditions associated with aortic growth. We also reported our experience of women who suffered aortic dissection (AoD), and who had preventive aortic replacement. METHODS: 151 adult TS were retrospectively identified. Women who had more than one transthoracic echocardiogram (TTE) after age 16 years were included in the aortic growth study. Aortic diameters at sinuses of Valsalva (SoV) and ascending aorta (AA) were analysed by two experts. RESULTS: 70/151 women had more than one TTE (interscan interval 4.7 years). Mean aortic growth was 0.13 ± 0.59 mm/year at SoV and 0.23 ± 0.82 mm/year at AA. Known risk factors for aortic dilatation and TS-related conditions were not associated with aortic growth. 4/151 women experienced AoD (age 25±8 years): two had paired scans for aortic growth, which was 0.67 mm/year at both SoV and AA in the first woman, and 11 mm/year (SoV) and 4 mm/year (AA) in the second. Only 1/4 of women with AoD survived; she used a TS cardiac-alert card to inform emergency personnel about her risk of AoD. 5/151 had a preventive aortic replacement, but one died post-operatively. CONCLUSIONS: Mean aortic growth in our TS population was increased compared to non-TS women and was not associated with currently known risk factors for AoD, suggesting that aortic growth rate itself could be a useful variable to stratify who is at risk for AoD.

New observations on minifascicular neuropathy with sex-dependent gonadal dysgenesis: a case series with nerve ultrasound assessment.

BACKGROUND: Gonadal dysgenesis with minifascicular neuropathy (GDMN) is a rare autosomal recessive condition associated with biallelic DHH pathogenic variants. In 46, XY individuals, this disorder is characterized by an association of minifascicular neuropathy (MFN) and gonadal dysgenesis, while in 46, XX subjects only the neuropathic phenotype is present. Very few patients with GDMN have been reported so far. We describe four patients with MFN due to a novel DHH likely pathogenic homozygous variant and the results of nerve ultrasound assessment. METHODS: This retrospective observational study included 4 individuals from 2 unrelated Brazilian families evaluated for severe peripheral neuropathy. Genetic diagnosis was performed with a peripheral neuropathy next-generation sequencing (NGS) panel based on whole exome sequencing focused analysis that included a control SRY probe to confirm genetic sex. Clinical characterization, nerve conduction velocity studies, and high-resolution ultrasound nerve evaluation were performed in all subjects. RESULTS: Molecular analysis disclosed in all subjects the homozygous DHH variant p.(Leu335Pro). Patients had a striking phenotype, with marked trophic changes of extremities, sensory ataxia, and distal anesthesia due to a sensory-motor demyelinating polyneuropathy. One 46, XY phenotypically female individual had gonadal dysgenesis. High-resolution nerve ultrasound showed typical minifascicular formation and increased nerve area in at least one of the nerves assessed in all patients. CONCLUSION: Gonadal dysgenesis with minifascicular neuropathy is a severe autosomal recessive neuropathy characterized by trophic alterations in limbs, sensory ataxia, and distal anesthesia. Nerve ultrasound studies are very suggestive of this condition and may help to avoid invasive nerve biopsies.

Monitoring and maintaining bone health in patients with Turner syndrome.

INTRODUCTION: Subjects affected with Turner Syndrome (TS) suffer low bone mineral density and high risk of fracture from a young age. Estrogen deficiency is considered the main risk factor but other factors, such as intrinsic bone abnormalities, enhanced osteoclastogenesis, vitamin D deficiency and other comorbidities may contribute to the exalted bone fragility. AREAS COVERED: The authors performed a literature search in PubMed and EMBASE, using selected key words. They focused their search on pathogenetic mechanisms of osteoporosis in TS and updated the diagnosis, prevention and therapeutic interventions. EXPERT OPINION: Bone health is a concern in subjects with TS, and strategies to prevent osteoporosis and fractures should be considered from childhood. Advice on how to live a healthy lifestyle, including physical activity and correct nutrition, should be given during childhood in order to prevent bone impairment later in life. The screening for vitamin D deficiency should be performed between the ages of 9 and 11, and every 2-3 years thereafter. Early initiation of estrogen replacement therapy (ERT) between 11-12 years of age, prompt titration to the adult dose after 2 years, and long-term follow-up to guarantee compliance with ERT, are the key points of osteoporosis prevention in women with TS.

The indication for fertility preservation in women with Turner syndrome should not only be based on the ovarian reserve but also on the genotype and expected future health status.

Fertility preservation in women with Turner syndrome is highly controversial. Some strongly recommend freezing of ovarian tissue at a young age, others do not. The controversy is partly due to different perspectives and professions. Biologists prefer to freeze young ovaries with high follicle density, reproductive physicians want to avoid risky operations and iatrogenic infertility by removing one ovary, and cardiologists and obstetricians warn against the risks of later pregnancies. Accordingly, fertility preservation in young women with Turner syndrome is more than just the freezing of ovarian tissue or oocytes. Fertility preservation requires a balanced decision considering the conservation of fertility, the protection of reproductive health, and future health consequences. Therefore, fertility preservation strategies should be based not only on the individual ovarian reserve but also on the genotype and the expected cardiac health status to decide what is the best option: to freeze tissue or alternatively to wait and see.

Prevalence, risk factors and management strategies for otological problems in girls with Turner syndrome.

AIM: To determine the prevalence and risk factors of ear disease in Turner syndrome (TS), propose an algorithm for future surveillance and recommend preventative strategies. METHODS: Review of TS patients seen in the West of Scotland between 1989 and 2015, with questionnaire follow-up in 2015. RESULTS: Of 168 girls, median age 27.3 (3.8-47.2) years, ear problems occurred more frequently with 45,X and 45,X/46,XiXq than other karyotypes: 71/103 (69%) versus 23/65 (35%). Recurrent acute otitis media (AOM) first developed at 0-5 years in 23 (40%) girls, persisting in 16 (10%) at 5-10 years; and first developing at 5-10 years in 11 (7%). Persistent otitis media with effusion (OME) first developed at 0-5 and 5-10 years in 23 (40%) and 14 (8%) girls. Recurrent AOM was significantly linked with cholesteatoma in 8 (4.9%) girls (7 aged >10 years). Permanent hearing loss was documented in 28 girls (16.7%), with 16 (9.5%) receiving hearing aids (bone-anchored in 3). CONCLUSION: Acute otitis media and OME occur commonly in preschool TS girls and may persist or newly develop in later childhood. Recurrent AOM predisposes to cholesteatoma. Strategies to reduce otological morbidity include: intensive patient education, annual audiology, vaccinations and a randomised trial of antibiotic prophylaxis in high-risk groups.

A critical assessment of case reports describing absent uterus in subjects with oestrogen deficiency.

OBJECTIVE: The dual diagnosis of hypoplastic uterus in association with ovarian dysgenesis is regularly reported but the pathogenesis of the association is unclear. The uterus, however, may be invisible to all imaging modalities without at least six months of exogenous oestrogen exposure in complete ovarian failure. We assessed all available case reports in this category to estimate whether the apparent association between primary ovarian insufficiency or Turner syndrome and Mullerian agenesis can be largely accounted for by oestrogen deficiency. DESIGN: A literature review of all cases in which an association between ovarian insufficiency or Turner syndrome and hypoplastic uterus has been reported. PATIENTS: PubMed was searched for all case reports associated with relevant key terms. In total, 22 publications with a total of 25 patients were identified and reviewed; 14 subjects had the normal female karyotype (46,XX), and 11 subjects had Turner Syndrome. MEASUREMENTS: Proportion of subjects who had been exposed to adequate oestrogen prior to the absent uterine diagnosis. RESULTS: A diagnosis of absent uterus was made prior to exposure to exogenous oestrogen in 22/25 (88%) of subjects with primary hypogonadism including 14/14 females with normal karyotype and 8/11 females with Turner syndrome. CONCLUSIONS: Oestrogen deficiency is a possible explanation for most subjects being reported as having Mullerian agenesis in association with Turner syndrome or primary ovarian insufficiency. In the presence of oestrogen deficiency, no conclusion can be made about the status of the uterus until adequate exposure to exogenous oestrogen has been completed and we suggest reassessment of the uterus when full adult dose has been reached towards the end of induction of puberty.

The assessment of skeletal status in young patients with Turner syndrome by 2 densitometric techniques: Phalangeal quantitative ultrasound and dual energy X-ray absorptiometry.

BACKGROUND: Studies using dual energy X-ray absorptiometry (DXA) demonstrate a reduction in bone mineral density (BMD) in children and adolescents with Turner syndrome (TS). However, these studies do not take into account changes in bone size, which influence BMD in the case of short-statured patients. Phalangeal quantitative ultrasound (phQUS) measurements have shown an ability to reveal changes due to skeletal growth, aging, and bone and mineral disorders. There is limited data on bone mineral status in girls with TS assessed by 2 different techniques, i.e., DXA and phQUS. OBJECTIVES: The aim of this study was to investigate the potential negative impact of TS on bone status and to assess whether densitometric values were related to former fractures. MATERIAL AND METHODS: In 43 TS girls aged 5-18 years, we evaluated bone status by 2 different densitometric techniques, DXA and phQUS. RESULTS: The mean lumbar spine areal bone mineral density (LS aBMD) Z-score was significantly lower than 0 (the hypothetical mean) compared to the reference population (p < 0.001). The mean LS aBMD height-adjusted Z-score did not differ significantly from 0. The amplitude-dependent speed of sound (Ad-SoS) Z-score was significantly lower than 0 compared with a Polish reference population. There were no significant differences between fractured and fracture-free patients as regards Ad-SoS Z-score and LS aBMD height-adjusted Z-score. CONCLUSIONS: Girls with TS have normal bone density adjusted for height, but significantly decreased phQUS values. Neither DXA nor phalangeal Ad-SoS can identify young TS patients with former fractures.

Resting energy expenditure in girls with Turner syndrome.

BACKGROUND: Knowledge concerning energy metabolism in Turner syndrome (TS) is lacking. We compared the resting energy expenditure per fat-free mass (REE/FFM) in TS with other girls with short stature treated with growth hormone (GH) and age-related controls. METHODS: We measured prospectively REE by spirometry under fasting conditions in the morning in 85 short prepubertal girls at the start of GH treatment. Diagnoses were TS (n=20), GH deficiency (GHD) (n=38) and small for gestational age (SGA) short stature (n=27). Additionally, 20 age-related controls were studied. Mean ages were 8.3 (TS), 7.1 (GHD), 6.9 (SGA) and 8.5 years (controls). Mean heights were -2.90 (TS), -3.32 (GHD), -3.69 (SGA) and -0.03 standard deviation scores (SDS) (controls). FFM was measured by bioelectrical impedance analysis (BIA). RESULTS: At the start of GH girls with TS showed insignificantly higher REE per FFM (REE/FFM) (mean±SD; 65±9 kcal/kg×day) than did the other female patients (62±9 kcal/kg×day) (p>0.23). The healthy controls had significantly lower REE/FFM (35±4 kcal/kg×day) (p<0.001). Follow-up examination of the patients after 6 or 12 months revealed decreasing REE/FFM in TS (62±9 kcal/kg×day) resulting in comparable REE/FFM in all three patient groups. CONCLUSIONS: At baseline short girls with TS had insignificantly higher REE/FFM than short children with SGA or GHD, but in follow-up this difference was not detectable any more. Future studies are necessary to understand this observation.

Assessment of the 21-hydroxylase deficiency and the adrenal functions in young females with Turner syndrome.

There are few reports of an association between Turner syndrome (TS) and 21-hydroxylase deficiency. However, this association is more frequent in some populations. The aim of this study was to evaluate the incidence of 21-hydroxylase deficiency in patients with TS in our population. 21-hydroxylase deficiency was evaluated in 44 TS cases with 45X (n=20) and 24 mosaic cases. A standard dose adrenocorticotropic (ACTH) stimulation test (Synacthen, Novartis, Basel, Switzerland) was performed, and 17 hydroxyprogesterone (17OHP), dehydroepiandrosterone sulfate (DHEAS) and cortisol responses were evaluated. Patients with increased 17OHP responses in the stimulation test also underwent 21-hydroxylase gene analysis. The mean age was 14.6 +/- 4 (2.6-22.4); 37 patients were on growth hormone (GH) treatment. Nine patients were at prepubertal stage, whereas 35 were pubertal (24 on gonadal steroids and 11 spontaneously). Six patients were obese. Only one of our patients had a level of 7.5 ng/mL of 17OHP, and there was no mutation found in congenital adrenal hyperplasia (CAH) genetic analysis. In other cases, peak 17OHP levels were < or = 6 ng/mL. The mean peak 17OHP was 2.62 +/- 1.48 (1.19-7.5) ng/mL, the cortisol level was 37.6 +/- 8.43 (23.9-56.2) microg/dL and the DHEAS was 135.2+/- 87.3 (15-413) microg/dL. The increased mean basal and peak cortisol levels (20.5 +/- 10.2 and 37.6 +/- 8.4 microg/dL) were remarkable findings. Whereas basal cortisol was above 20 microg/dL in 38.7% of patients, exaggerated results up to 56.2 microg/dL were obtained in peak cortisol levels. The basal and peak 17OHP cortisol levels were not correlated with the presence of puberty, chromosome structure, gonadal steroid use, obesity or growth hormone use. This trial suggested that 21-hydroxylase deficiency was not common among patients with TS in our population. Adrenal function should be assessed, at least in the presence of clitoral enlargement in patients with TS, particularly if their karyotype does not contain a Y chromosome.

Selecting barrenness: the use of preimplantation genetic diagnosis by congenitally infertile women to select for infertility.

Congenitally infertile women such as those with Turner syndrome or Mayer Rokitansky-Kuster-Hauser syndrome have available the technologies of oocyte harvesting, cryropreservation, in-vitro fertilization, and gestational surrogacy in order to have genetically related offspring. Since congenital infertility results in a variety of experiences that impacts on nearly every aspect of a person's life, in the future it is possible that these women might desire a congenitally infertile child through the use of preimplantation genetic diagnosis so as to share this common bond. While infertility results in a relatively normal quality of life, it is morally wrong to necessitate the future use of infertility services with its variable success rate on a child. Also, whereas the woman has fundamental reproductive autonomy, she lacks the substantive autonomy regarding the specific characteristics of her child. Finally, the infertile community does exhibit a strong presence, but it lacks characteristics that define it as a culture.

[Functional assessment in girls with Turner syndrome--preliminary results]. / Problemy funkcjonalne pacjentek z zespolem Turnera--doniesienie wstepne.

INTRODUCTION: About 10% of Turner's syndrome (TS) patients complain on persistent knee pain, and seek the orthopaedic help because of it. AIM OF STUDY: To evaluate the gait pattern of girls with TS. MATERIAL AND METHODS: Gait analysis was performed using VICON 460 system in 15 patients aged 7 to 20 years. The maximal isometric flexion and extension moments of the knee joints were measured. The knees were examined with X-ray and USG for possible anatomical or degenerative changes. RESULTS: All spatio-temporal parameters of the gait were within normal values. Only 3 patients had proper pelvic tilt, all the others had decreased tilt (from 2 to 9). Only 40% had proper knee flexion at initial contact, 1 patient had knee hyperextension, all the others increased knee flexion. In 50% of the patients the decreased knee range of motion together with decreased maximum knee flexion in swing phase was observed. In 30% there was a decreased hip range of motion. Clinical evaluation of body posture revealed that nearly all patients had trunk asymmetry, and various deformities of knees and feet. DISCUSSION: Nearly all TS patients had decreased pelvic tilt, which could be sign of the weakness of the muscles responsible for the pelvis orientation. The abnormalities of upper and lower body found during clinical evaluation of body posture also suggested decreased muscular strength. It is known that girls with TS have poorer motor development, which could result in decreased muscular strength and our findings support this thesis. Decreased muscular strength could also negatively influence the locomotor abilities.

Growth hormone use in pediatric growth hormone deficiency and other pediatric growth disorders.

The diagnosis and management of growth disorders in children, particularly disorders that respond to therapy with growth hormone (GH), raise challenging clinical and economic issues. Several such issues are presented in the following article in which Dr. Ron Rosenfeld examines the evaluation and diagnosis of the child with short stature; Dr. David B. Allen discusses the anabolic and metabolic indications for GH treatment in children; Dr. Margaret H. MacGillivray reviews GH dosing, height outcomes, and follow up; and Dr. Craig Alter presents the payer's perspective on the diagnosis and treatment of pediatric GH deficiency. In addressing the use of GH in other pediatric populations, Dr. Paul Saenger focuses on Turner syndrome, Dr. Henry Anhalt on chronic renal insufficiency of childhood, and Dr. Ray Hintz on idiopathic short stature. Dr. Harvey P. Katz presents one managed care organization's policy and implementation plan that is used to guide decisions regarding coverage for GH treatment.

Clinician and payer issues in managing growth hormone deficiency.

Growth hormone (GH) therapy has an established record of efficacy in the treatment of children with proven GH deficiency. It has also shown benefit, including nongrowth-related benefit, in other nontraditional pediatric uses, but managed care plans hesitate to reimburse clinicians for such uses. In adults and in those individuals who are in transition from GH-deficient children to adults, GH deficiency is sometimes difficult to diagnose. In such cases, growth rate cannot be used to guide therapy and the outcomes measures are either "softer" (e.g., quality of life) or very long term (e.g., bone mineral density changes). Also, there are no long-term data to show GH treatment in adults affects the cardiovascular-associated morbidity and mortality from GH deficiency. However, several cardiovascular risk factors, such as hypercholesterolemia and abdominal adiposity, improve in GH-deficient adults who receive GH treatment. Clinicians and payers often appear at odds with each other over their primary goals for managing the various forms of GH deficiency. However, upon closer examination, both parties do share common treatment goals and strive to do the right clinical thing. Identifying the cost of treatment emphasizes the need for evidence-based medicine.

Growth hormone: do we have a national perspective of indications for its use?

OBJECTIVE: Presentation of indications for growth hormone use in children, from the view of physicians practising in Saudi Arabia. METHODS: A questionnaire containing a list of common possible indications of growth hormone use was collected from 52 physicians practising in Saudi Arabia who were attending a didactic endocrinology course. RESULTS: All (100%) physicians considered growth hormone deficiency to be an indication. Sixty four and 29% considered Turner's syndrome and chronic renal failure to be indications. Other indications included Russell-Silver syndrome in 23%, X-linked hypophosphatemic rickets in 10%, Achondroplasts in 10%, Sickle cell anemia in 10% and Bartter's syndrome in 2%. Genetic and constitutional short stature were considered in 17 and 19%. Only 65% did not advocate the use of growth hormone for short non-growth hormone-deficient children. CONCLUSION: Indications of growth therapy are not clearly defined in Saudi Arabia. It is indicated to define this by a clear, national decided criteria which should take into consideration the internationally approved indications, availability and cost of this hormone.

Assessment of Turner's syndrome by molecular analysis of the X chromosome in growth-retarded girls.

Turner's syndrome (TS) is a common disorder (1/2500 to 1/5000 female births) which is diagnosed at birth in approximately 20% of patients and during childhood or at puberty for the rest. Growth retardation is the most frequent clinical feature of TS, so we systematically searched for TS in female patients referred to our center because of short stature. Three hundred seventy-five female patients, 1 month to 18 yr old (mean +/- SD = 9(7/12) +/- 3(9/12), with growth retardation (less than -2 SD) and/or decreased height velocity were included in the study. Mean growth retardation was -2.57 SD +/- 0.79 (range: -1 to -7). Thirty-two percent of the patients had reached puberty. GH provocative tests were performed in 329 patients (87.7%), and 36 of these patients (11%) had impaired GH secretion (5 complete and 31 partial GH deficiency). TS was evaluated by Southern blot analysis of leukocyte DNA using a multiallelic polymorphic X chromosome marker (88% heterozygosity rate). Y chromosome PCR analysis was carried out if a pattern indicative of TS was obtained. Leukocyte DNA analysis produced an abnormal restriction pattern for 20 of the 375 cases (5.3%). There was a single hybridizing band in 13 cases, an allelic disproportion indicative of mosaicism in 6 cases, and 3 hybridizing bands in 1 case. One patient tested positive in the Y chromosome PCR analysis. Cytogenetic analysis showed 47 XXX trisomy in the patient with a 3-hybridizing-band pattern and confirmed the diagnosis of TS for 17 of the 19 suspected cases: 45 X: n = 7; 45 X/46 Xi(Xq): n = 4; 45 X/46 XX: n = 2; 46 Xi(Xq): n = 1; 45 X/46 Xr(X): n = 1; 45 X/46 XX/47 XXX: n = 1; 45 X/46 XY: n = 1. Cytogenetic analysis was normal (46 XX) for the 2 other patients. The TS phenotype is variable: dysmorphism is often missing or mild (particularly in cases of mosaicism), but growth is reduced in virtually all patients. Screening of 375 growth-retarded girls identified 18 cases of TS, of which 17 were diagnosed by molecular analysis. This incidence (4.8%) was significantly higher than the expected incidence in this population (0.8-1.6%: P < 0.001).