Copy number variation of two separate regulatory regions upstream of SOX9 causes isolated 46,XY or 46,XX disorder of sex development.

BACKGROUND: SOX9 mutations cause the skeletal malformation syndrome campomelic dysplasia in combination with XY sex reversal. Studies in mice indicate that SOX9 acts as a testis-inducing transcription factor downstream of SRY, triggering Sertoli cell and testis differentiation. An SRY-dependent testis-specific enhancer for Sox9 has been identified only in mice. A previous study has implicated copy number variations (CNVs) of a 78 kb region 517-595 kb upstream of SOX9 in the aetiology of both 46,XY and 46,XX disorders of sex development (DSD). We wanted to better define this region for both disorders. RESULTS: By CNV analysis, we identified SOX9 upstream duplications in three cases of SRY-negative 46,XX DSD, which together with previously reported duplications define a 68 kb region, 516-584 kb upstream of SOX9, designated XXSR (XX sex reversal region). More importantly, we identified heterozygous deletions in four families with SRY-positive 46,XY DSD without skeletal phenotype, which define a 32.5 kb interval 607.1-639.6 kb upstream of SOX9, designated XY sex reversal region (XYSR). To localise the suspected testis-specific enhancer, XYSR subfragments were tested in cell transfection and transgenic experiments. While transgenic experiments remained inconclusive, a 1.9 kb SRY-responsive subfragment drove expression specifically in Sertoli-like cells. CONCLUSIONS: Our results indicate that isolated 46,XY and 46,XX DSD can be assigned to two separate regulatory regions, XYSR and XXSR, far upstream of SOX9. The 1.9 kb SRY-responsive subfragment from the XYSR might constitute the core of the Sertoli-cell enhancer of human SOX9, representing the so far missing link in the genetic cascade of male sex determination.

Outcomes of adenotonsillectomy in patients with Prader-Willi syndrome.

OBJECTIVE: To assess the efficacy of upper airway surgical intervention in patients with Prader-Willi syndrome (PWS). Due to reports of sudden death in children undergoing treatment with growth hormone for PWS, detection of sleep-disordered breathing by polysomnography (PSG) has been recommended. DESIGN: Retrospective study. SETTING: Multidisciplinary PWS Center at a tertiary care children's hospital. PATIENTS: Thirteen pediatric patients with PWS who underwent adenotonsillectomy (T&A) with pre-PSG and post-PSG. MAIN OUTCOME MEASURES: Comparison of PSG results before and after T&A. RESULTS: Six of our patients were girls (46%); 8 had genetic characteristics consistent with deletion (61%), and the remaining 5 had genetic characteristics consistent with uniparental disomy (39%). The median age at T&A was 3 years (age range, 6 months to 11 years), and the median age at start of growth hormone treatment was 8.5 months (range, 2 months to 6 years). Nine of the 13 patients had mild to moderate obstructive sleep apnea (OSA) or obstructive hypoventilation (69%); in 8 of these 9, breathing normalized after T&A. Four children had severe OSA prior to surgery (31%). Breathing normalized in 2 of these after surgery, but 2 had PSG findings of residual combined obstructive and central apneas postoperatively. CONCLUSIONS: Adenotonsillectomy, while effective in most children with PWS who demonstrate mild to moderate OSA, may not be curative in children with severe OSA. An increase in central apneas can occur in some children with PWS postoperatively, and it is important to repeat PSG after surgery. Further studies are necessary to determine optimal treatment for some children with PWS and sleep-disordered breathing.

Growth hormone treatment of adults with Prader-Willi syndrome and growth hormone deficiency improves lean body mass, fractional body fat, and serum triiodothyronine without glucose impairment: results from the United States multicenter trial.

CONTEXT: GH replacement in Prader-Willi syndrome (PWS) children has well-defined benefits and risks and is used extensively worldwide. Its use in PWS adults has been limited by documentation of benefits and risks, as determined by larger multisite studies. OBJECTIVES: Our objective was to evaluate the effectiveness and safety of GH in GH-deficient genotype-positive PWS adults. DESIGN: We conducted a 12-month open-label multicenter trial with 6-month dose-optimization and 6-month stable treatment periods. SETTING: The study was conducted at outpatient treatment facilities at four U.S. academic medical centers. PATIENTS: Lean and obese PWS adults with diverse cognitive skills, behavioral traits, and living arrangements were recruited from clinical populations. INTERVENTION: Human recombinant GH (Genotropin) was initiated at 0.2 mg/d with monthly 0.2-mg increments to a maximum 1.0 mg/d, as tolerated. MAIN OUTCOMES MEASURES: Lean body mass and percent fat were measured by dual-energy x-ray absorptiometry. RESULTS: Lean body mass increased from 42.65 +/- 2.25 (se) to 45.47 +/- 2.31 kg (P < or = 0.0001), and percent fat decreased from 42.84 +/- 1.12 to 39.95 +/- 1.34% (P = 0.025) at a median final dose of 0.6 mg/d in 30 study subjects who completed 6-12 months of GH. Mean fasting glucose of 85.3 +/- 3.4 mg/dl, hemoglobin A1c of 5.5 +/- 0.2%, fasting insulin of 5.3 +/- 0.6 microU/ml, area under the curve for insulin of 60.4 +/- 7.5 microU/ml, and homeostasis model assessment of insulin resistance of 1.1 +/- 0.2 were normal at baseline in 38 study initiators, including five diabetics, and remained in normal range. Total T(3) increased 26.7% from 127.0 +/- 7.8 to 150.5 +/- 7.8 ng/dl (P = 0.021) with normalization in all subjects, including six (20%) with baseline T(3) values at least 2 sd below the mean. Mildly progressive ankle edema was the most serious treatment-emergent adverse event (five patients). CONCLUSIONS: This multicenter study demonstrates that GH improves body composition, normalizes T(3), and is well tolerated without glucose impairment in PWS genotype adults.

Growth hormone treatment and adverse events in Prader-Willi syndrome: data from KIGS (the Pfizer International Growth Database).

OBJECTIVE: To evaluate the response to recombinant GH treatment and adverse events in children with Prader-Willi syndrome (PWS) from KIGS, the Pfizer International Growth Database. PATIENTS: A total of 328 children (274 prepubertal, median age 6.0 years; 54 pubertal, median age 12.7 years) were treated for 1 year and 161 children were treated for 2 years with GH. RESULTS: Height standard deviation score (SDS) increased significantly during treatment; the response was greater in prepubertal (-0.7 vs.-1.8 pretreatment) compared with pubertal children (-1.5 vs.-1.8). Predictors of first-year height velocity in multiple regression analysis were GH dose, body weight (positively correlated), height SDS minus mid-parental height SDS and chronological age (negatively correlated), together accounting for 39% of the variation in response to GH. Body mass index (BMI) SDS did not change significantly during 2 years of treatment. Of all the 675 GH-treated PWS patients in KIGS, there were five cases of sudden death (age range 3-15 years). Three were obese (weight for height > 200%) and causes of death included bronchopneumonia, respiratory insufficiency and sleep apnoea. Scoliosis was the most commonly reported adverse event (n = 24), four children developed hyperglycaemia and six had presumptive diabetes (type 2 in five, and one case of type 1). CONCLUSIONS: Short-term growth improved in response to conventional doses of GH in children with PWS. Prior to commencement of GH, examination of the upper airways and sleep studies should be performed in PWS patients. GH should be used with caution in those with extreme obesity or disordered breathing and all patients should be closely monitored for adverse events.

Puberty-timing is everything!

Puberty is a dynamic period of physical growth, sexual maturation, and psychosocial achievement that generally begins between age 8 and 14 years. The age of onset varies as a function of sex, ethnicity, health status, genetics, nutrition, and activity level. Puberty is initiated by hormonal changes triggered by the hypothalamus. Children with variants of normal pubertal development--both early and late puberty--are common in pediatric practice. Recognizing when variations are normal and when referral for further evaluation is indicated is an important skill.

Prader-Willi syndrome: the care and treatment of infants, children, and adults.

With appropriate intervention, the clinical course of children with PWS can be changed for the better. Individuals who have had the benefit of early diagnosis and treatment will have more normal (although generally still excessive) weight, less severe short stature, less persistent hypotonia, and significantly improved mobility and activity than would otherwise be possible. With proper care, the behavior problems, while significant, are manageable. The expected lifespan of individuals with PWS who have received anticipatory care and appropriate attention to medical problems has yet to be determined but can be beyond 30 to 40 years and can be associated with an absence of the related major comorbidities and a markedly improved quality of life.