Antonio Balsamo

Characterization of deletions at 9p affecting the candidate regions for sex reversal and deletion 9p syndrome by MLPA

The distal region on the short arm of chromosome 9 is of special interest for scientists interested in sex development as well as in the clinical phenotype of patients with the 9p deletion syndrome, characterized by mental retardation, trigonocephaly and other dysmorphic features. Specific genes responsible for different aspects of the phenotype have not been identified. Distal 9p deletions have also been reported in patients with 46,XY sex reversal, with or without 9p deletion syndrome. Within this region the strongest candidates for the gonadal dysgenesis phenotype are the DMRT genes; however, the genetic mechanism is not clear yet. Multiple ligation-dependent probe amplification represents a useful technique to evaluate submicroscopic interstitial or distal deletions that would help the definition of the minimal sex reversal region on 9p and could lead to the identification of gene(s) responsible of the 46,XY gonadal disorders of sex development (DSD). We designed a synthetic probe set that targets genes within the 9p23-9p24.3 region and analyzed a group of XY patients with impaired gonadal development. We characterized a deletion distal to the DMRT genes in a patient with isolated 46,XY gonadal DSD and narrowed down the breakpoint in a patient with a 46,XY del(9)(p23) karyotype with gonadal DSD and mild symptoms of 9p deletion syndrome. The results are compared with other patients described in the literature, and new aspects of sex reversal and the 9p deletion syndrome candidate regions are discussed.

Randomised trial of LHRH analogue treatment on final height in girls with onset of puberty aged 7.5–8.5 years

OBJECTIVE To study the effectiveness of luteinising hormone releasing hormone (LHRH) analogues in improving final height in girls affected by early puberty. PATIENTS Forty six consecutive girls with onset of puberty aged 7.5–8.5 years randomly divided into two groups: one treated with 3.75 mg triptorelin intramuscularly every four weeks (group 1); and the other with no treatment (group 2). RESULTS Mean (SD) chronological age at onset of menarche was significantly higher in group 1 than in group 2 (11.9 (1.0) v 10.8 (0.7) years). However, mean (SD) height at menarche (152.7 (7.2)v 152.5 (5.7) cm) and mean (SD) growth after menarche (4.9 (3.0) v 5.4 (2.2) cm) were similar in both groups. The mean (SD) final height was similar in the two groups (group 1, 158.1 (6.2) cm; group 2, 158.6 (6.0) cm) and not significantly different from target height. Fourteen of 20 patients in group 1 and 12 of 18 patients in group 2 showed final height equal to or higher than target height. Final heights of girls with poor initial height prognosis were significantly lower than those of girls with good prognosis, but in patients with the same initial height prognosis, both groups showed final heights similar and not significantly different from their target heights. CONCLUSIONS LHRH analogue has no apparent effect on final height in subjects with onset of puberty between 7.5 and 8.5 years.

How many cases of true precocious puberty in girls are idiopathic

Fifteen girls with true precocious puberty were examined by computerized tomography. In seven hypothalamic hamartomas were suspected. A pneumoencephalogram was performed in six cases (one patient refused), with the following results. In five, the radiological features were highly suggestive of tuber cinereum hamartoma. All of our patients with pubertal signs appearing before the age of 2 years and 80% of the girls with early menstruation were in the group with suspected hamartoma. The luteinizing hormone and follicle-stimulating hormone levels of these five girls were significantly higher than those observed in the other girls with idiopathic precocious puberty. We conclude that there is a high frequency of small hypothalamic masses (suspected hamartoma) in girls with true precocious puberty (33% of the patients in our group), that it is important to confirm the presence of the mass with pneumoencephalography, and that surgery for diagnostic and therapeutic purposes should be carefully considered, given the absence of any neurologic symptoms for a long time after the appearance of the first pubertal signs.

CYP21 analysis and phenotype/genotype relationship in the screened population of the Italian Emilia–Romagna region

We have genotyped the patients with congenital adrenal hyperplasia due to 21‐hydroxylase deficiency identified from March 1980 to December 1997 through a combined program of neonatal screening and case survey in the Emilia–Romagna Region (Italy). We have also analysed retrospectively the possible advantages of genotypical neonatal classification.

McCune-Albright syndrome: A longitudinal clinical study of 32 patients

We report the diagnostic clinical features and their long term evolution in 32 patients with McCune-Albright syndrome. Patient data are made up of two periods: the first, classified as personal history, is from birth until the time when the diagnosis of McCune-Albright syndrome was made; the second, classified as clinical observation, is from the first observation until the end of follow up. The total duration of these two periods was 9.6+/-2.9 yr; mean age at first observation was 5.7 yr (range 0.7-11 yr). The probability of manifesting main clinical signs according to age was calculated: almost all had skin dysplasia at birth, 50% probability of peripheral precocious puberty in females at 4 years and 50% of bone dysplasia at 8 years of age were found. Other clinical signs had diagnostic relevance when preceding the main signs leading to diagnosis of McCune-Albright syndrome even without specific genetic investigation. The most important clinical manifestations have different evolutions: skin lesions increase in dimensions according to body growth; precocious puberty in females evolves rapidly but periods of regression can be seen in some patients; bone dysplasia in most patients evolves with an increase both in the number of affected bones and in the severity of lesions.

Changes Over Time in Sex Assignment for Disorders of Sex Development

BACKGROUND AND OBJECTIVE: It is unclear whether the proportion of infants with a disorder of sex development who are raised as male or female has changed over time. The temporal trends in sex assignment of affected cases entered in the International Disorder of Sex Development (I-DSD) Registry were studied. METHODS: Cases of disorders of sex development reported as partial androgen insensitivity syndrome (PAIS; n = 118), disorder of gonadal development (DGD; n = 232), and disorder of androgen synthesis (DAS; n = 104) were divided into those who were born before 1990, 1990–1999, and after 1999. External appearance of the genitalia was described by the external masculinization score. RESULTS: The median (5th–95th percentile) external masculinization scores of those infants with PAIS, DGD, and DAS who were raised as boys were 6 (2–9), 6 (3–9), and 6 (1–12), respectively, and were significantly higher than in those raised as girls (2 [0–6], 2 [0–7], and 0 [0–5], respectively); this difference was maintained in the 3 temporal birth cohorts (P < .01). Of the 118 cases in the pre-1990 cohort, 41 (35%) were raised as boys; of the 148 cases in the 1990–1999 cohort, 60 (41%) were raised as boys; and of the 188 cases in the post-1999 cohort, 128 (68%) were raised as boys. CONCLUSIONS: Although there is an association between the external appearance of the genitalia and the choice of sex assignment, there are clear temporal trends in this practice pointing toward an increased likelihood of affected infants being raised as boys. The impact of this change in practice on long-term health outcomes requires additional focus.

High Prevalence of Precocious Puberty and Obesity in Childhood Narcolepsy with Cataplexy

STUDY OBJECTIVES We analyzed the potential predictive factors for precocious puberty, observed in some cases of childhood narcolepsy with cataplexy (NC) and for obesity, a much more common feature of NC, through a systematic assessment of pubertal staging, body mass index (BMI), and metabolic/endocrine biochemical analyses. DESIGN Cross-sectional on consecutive recruitment. SETTING Hospital sleep center and pediatric unit. PATIENTS Forty-three children and adolescents with NC versus 52 age-matched obese children as controls. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Patients underwent clinical interview, polysomnographic recordings, cerebrospinal fluid hypocretin-1 measurement, and human leukocyte antigen typing. Height, weight, arterial blood pressure, and Tanner pubertal stage were evaluated. Plasma lipid and glucose profiles were analyzed. When an altered pubertal development was clinically suspected, plasma concentrations of hypothalamic-pituitary-gonadal axis hormones were determined. Children with NC showed a high prevalence of overweight/obesity (74%) and a higher occurrence of precocious puberty (17%) than obese controls (1.9%). Isolated signs of accelerated pubertal development (thelarche, pubic hair, advanced bone age) were also present (41%). Precocious puberty was significantly predicted by a younger age at first NC symptom onset but not by overweight/obesity or other factors. In addition, overweight/obesity was predicted by younger age at diagnosis; additional predictors were found for overweight/obesity (short disease duration, younger age at weight gain and lower high-density lipoprotein cholesterol), which did not include precocious puberty. NC symptoms, pubertal signs appearance, and body weight gain developed in close temporal sequence. CONCLUSIONS NC occurring during prepubertal age is frequently accompanied by precocious puberty and overweight/obesity, suggesting an extended hypothalamic dysfunction. The severity of these comorbidities and the potential related risks require a multidiagnostic approach and a tailored therapeutic management.

Influence of growth hormone on thymic endocrine activity in humans

The thymus produces humoral factors that induce the proliferation and differentiation of T cells which are responsible for cell-mediated immunity. Experimental data have suggested that this thymic hormone production is modulated by the neuroendocrine network and, in particular, by growth hormone (GH) and thyroid hormones. To study the role played by GH in thymic endocrine activity in humans, the circulating level of one of the best known thymic peptides, i.e. thymulin (Zn-FTS), has been determined, after a washout period of 2 weeks without GH treatment, in GH-deficient children before and after a single injection of GH. The basal thymulin level is consistently lower in GH-deficient children than in healthy age-matched controls. A single injection of GH induces a significant increment of the thymulin level for at least 48 h. Since thymulin activity may also depend on zinc bioavailability, on thyroid hormone turnover and on the eventual presence of thymulin-inhibitory substances, all these aspects have been checked. No supporting evidence regarding the existence of these kinds of interferences in GH-deficient children has been substantiated. A positive correlation has been found between the serum level of insulin-like growth factor I, but not of GH, and thymulin activity. These data suggest that GH may directly or indirectly modulate the thymic endocrine function in humans. Whether and to what extent such a modulation is relevant to the functioning of the immune system remains to be ascertained.

Novel associations in disorders of sex development: Findings from the I-DSD registry

Context: The focus of care in disorders of sex development (DSD) is often directed to issues related to sex and gender development. In addition, the molecular etiology remains unclear in the majority of cases. Objective: To report the range of associated conditions identified in the international DSD (I-DSD) Registry. Design, Setting, and Patients: Anonymized data were extracted from the I-DSD Registry for diagnosis, karyotype, sex of rearing, genetic investigations, and associated anomalies. If necessary, clarification was sought from the reporting clinician. Results: Of 649 accessible cases, associated conditions occurred in 168 (26%); 103 (61%) cases had one condition, 31 (18%) had two conditions, 20 (12%) had three conditions, and 14 (8%) had four or more conditions. Karyotypes with most frequently reported associations included 45,X with 6 of 8 affected cases (75%), 45,X/46,XY with 19 of 42 cases (45%), 46,XY with 112 of 460 cases (24%), and 46,XX with 27 of 121 cases (22%). In the 112 cases of 46,XY DSD, the commonest conditions included small for gestational age in 26 (23%), cardiac anomalies in 22 (20%), and central nervous system disorders in 22 (20%), whereas in the 27 cases of 46,XX DSD, skeletal and renal anomalies were commonest at 12 (44%) and 8 (30%), respectively. Of 170 cases of suspected androgen insensitivity syndrome, 19 (11%) had reported anomalies and 9 of these had confirmed androgen receptor mutations. Conclusions: Over a quarter of the cases in the I-DSD Registry have an additional condition. These associations can direct investigators toward novel genetic etiology and also highlight the need for more holistic care of the affected person.

Gene dosage imbalances in patients with 46,XY gonadal DSD detected by an in-house-designed synthetic probe set for multiplex ligation-dependent probe amplification analysis.

The development of a testis requires the proper spatiotemporal expression of the SRY gene and other genes that act in a dosage‐sensitive manner. Mutations in the SRY gene account for only 10–15% of patients with 46,XY gonadal disorder of sex development (DSD). To enable the diagnostics of deletions and duplications of genes known to be involved in different forms of DSD, we developed a synthetic probe set for multiplex ligation‐dependent probe amplification (MLPA) analysis. Here, we report the results from the analysis of 22 patients with 46,XY gonadal DSD. The analysis with the DSD probe set has led to the identification of two copy number variations, an 800‐kb NR0B1 (DAX1) locus duplication on Xp21 in a patient with isolated partial gonadal dysgenesis and a duplication of the SRD5A2 gene that represents a rare normal variant. The described MLPA kit represents an optimal complement to DNA sequence analysis in patients with DSD, enabling screening for deletions and duplications of several genes simultaneously. Furthermore, the second identification of an NR0B1 locus duplication in a patient with isolated gonadal dysgenesis, without dysmorphic features and/or mental retardation, highlights the importance of evaluating NR0B1 duplication in patients with gonadal dysgenesis.