Insights into genotype-phenotype correlations from CREBBP point mutation screening in a cohort of 46 Rubinstein-Taybi syndrome patients.

The genetic basis of Rubinstein-Taybi syndrome (RSTS), a rare, sporadic, clinically heterogeneous disorder characterized by cognitive impairment and a wide spectrum of multiple congenital anomalies, is primarily due to private mutations in CREBBP (approximately 55% of cases) or EP300 (approximately 8% of cases). Herein, we report the clinical and the genetic data taken from a cohort of 46 RSTS patients, all carriers of CREBBP point mutations. Molecular analysis revealed 45 different gene alterations including 31 inactivating (21 frameshift and 10 nonsense), 10 missense and 4 splicing mutations. Bioinformatic tools and transcript analyses were used to predict the functional effects of missense and splicing alterations. Of the 45 mutations, 42 are unreported and 3 were described previously. Recurrent mutations maybe a key tool in addressing genotype-phenotype correlations in patients sharing the same defects (at the genomic or transcript level) and specific clinical signs, demonstrated here in two cases. The clinical data of our cohort evidenced frequent signs such as arched eyebrows, epicanthus, synophrys and/or frontal hypertrichosis and broad phalanges that, previously overlooked in RSTS diagnosis, now could be considered. Some suggested correlations between organ-specific anomalies and affected CREB-binding protein domains broaden the RSTS clinical spectrum and perhaps will enhance patient follow-up and clinical care.

Common polymorphisms of the growth hormone (GH) receptor do not correlate with the growth response to exogenous recombinant human GH in GH-deficient children.

CONTEXT: GH acts through the GH receptor (GHR), whose polymorphisms might affect the growth response to recombinant human GH (rhGH). OBJECTIVE: The objective of this study was to investigate possible influences of GHR polymorphisms on the growth response to rhGH in GH-deficient (GHD) children. DESIGN: This was a 2-yr study (first year, spontaneous growth; second year, growth during rhGH treatment). SETTING: This study was performed at a referral center. PATIENTS: Fifty-four prepubertal GHD children (11 females; mean age, 7.8 yr; sd, 3.96) were studied. INTERVENTION: Patients were treated with rhGH (0.2 mg/kg.wk) for at least 1 yr after diagnosis. Growth velocity (GV) was measured 1 yr before treatment and during the first treatment year. GHR exons were amplified by PCR using pairs of intronic primers. The presence of single or multiple mismatches in the PCR products was revealed by denaturing high-pressure liquid chromatography. For exons in which mismatches were found by denaturing high-pressure liquid chromatography, direct sequencing was performed by automatic sequencer. MAIN OUTCOME MEASURES: Before the start of treatment, the mean height (Ht) sd score was -1.93 (sd, 0.70), and the mean GV sd score was -1.49 (sd, 1.26). RESULTS: The posttreatment (first 12 months) mean GV sd score was 3.55 (sd, 3.27). Molecular analysis revealed a high frequency of GHR polymorphisms; in particular: exon 3 deletion (Del 3) in 26 subjects (48%), polymorphism 504 A>G at codon 168 of exon 6 in 44 (82%), and polymorphism 1576 A>C at codon 526 of exon 10 in 35 (65%). In most patients, these different polymorphisms recurred in association. We found no significant differences in GV between the groups of subjects defined by the polymorphic genotypes. CONCLUSION: The most common GHR polymorphisms, alone or in association, do not appear to affect the growth response to rhGH in GHD children.

Frasier syndrome with childhood-onset renal failure.

BACKGROUND: The Wilms' tumour 1 (WT1) gene encodes a protein which is believed to exert transcriptional and tumour-suppressor activities. Mutations of this gene have occasionally been associated with Wilms' tumour (<15% of cases) and, more consistently, with three syndromes characterized by urogenital abnormalities (WAGR, Denys-Drash and Frasier syndrome). SUBJECT/METHOD: A 25-year-old phenotypic female with a 46,XY karyotype presented with amenorrhoea. An ultrasound scan showed streak gonads and a rudimentary uterus. The patient had a history of post-streptococcal glomerulonephrosis, when aged 4 years, which had rapidly progressed to kidney failure, requiring transplantation at age 8. RESULT: Frasier syndrome was suspected and confirmed by genetic analysis. In fact, direct sequencing of the PCR product of the intron 9 donor splice site revealed a substitution of guanine for adenine in position +5. CONCLUSION: Besides being one of the few Frasier syndrome cases to be genetically characterized, this case is interesting because of the unusually early-onset renal failure.

Etiology of central precocious puberty in males: the results of the Italian Study Group for Physiopathology of Puberty.

We reviewed the hospital records of 45 boys, followed in 13 pediatric departments throughout Italy, who had undergone computed tomography and/or magnetic resonance imaging for central precocious puberty (CPP). Twenty-seven patients (60%) had idiopathic CPP and 18 (40%) neurogenic CPP. A hamartoma of the tuber cinereum was found in six patients (33%). All patients with hypothalamic hamartoma had earlier onset of symptoms than patients with idiopathic CPP. Five patients (27%) were affected by type 1 neurofibromatosis, two had ependymoma and five patients had an intracranial anomaly. Basal LH and basal and peak LH/FSH ratio were greater, but not significantly, in boys with neurogenic CPP than in boys with idiopathic CPP. The highest LH peak levels were observed in patients with hamartoma; however, no correlation was observed between LH peak and the size of the hamartomas. In addition, bone age at diagnosis was more advanced in patients with hamartoma than in patients with other conditions. In conclusion, gonadotrophin-dependent precocious puberty may be of idiopathic origin or may occur in association with any CNS disorder. Further studies are needed in order to evaluate the effects of nutritional, environmental and psychosocial factors on the timing of sexual maturation, to explain the high incidence of idiopathic CPP in our male patients.

Pelvic ultrasonography in normal girls and in girls with pubertal precocity.

UNLABELLED: This prospective study sought to evaluate the role of pelvic ultrasonography in differentiating between various types of pubertal precocity. A control group of 117 normal girls (aged 1.1-15.6) was studied and compared with 87 girls with premature sexual maturation (aged 1.1-9.2 y). Of these patients 19 had central precocious puberty (CPP), 48 had isolated premature thelarche (IPT) and 20 had premature adrenarche (IPA). Pelvic ultrasound variables evaluated were: (i) uterus: longitudinal diameter (uterine length), cross-sectional area (CSA) and fundo-cervical ratio; and (ii) ovaries: volume and morphology. Ovarian morphology was subdivided in 6 different appearances: solid, microcystic, paucicystic, multicystic, macrocystic, and major isolated cyst. In normal control girls, uterine length and CSA increased with age, although no cut-off values could be defined between different age ranges, and they were correlated with breast stage; fundo-cervical ratio was stable through childhood and increased after age 9. Ovarian volume was significantly greater in pubertal girls with breast stage 2 than in those with only pubic and/or axillary hair. There was a clear predominance of solid ovarian appearances in the age range 2-7, with the multicystic appearance being seen only after age 7, a minority being macrocystic. After age 10 all the different patterns were observed, and after age 13 the frequency of a macrocystic pattern increased. Significantly more mature ovarian appearances were observed in subjects with breast development compared with those without, independently of the presence of pubic hair. Patients with IPT had no significant differences in pelvic ultrasound measurements when compared with age-matched controls. All the different morphological ovarian appearances were observed in IPT, in contrast to age-matched controls, where only the less mature patterns (solid, micro- and paucicystic) were seen. Patients with CPP had significantly more mature patterns of ovarian morphology compared with age-matched controls, but did not differ from pubertal pre-menarcheal controls. Those patients with IPA differed from age-matched controls only in having significantly greater uterine length and CSA. Comparison of the pelvic ultrasound parameters between patient groups (IPT, CPP, IPA) and age-matched controls revealed significantly higher values in CPP for uterine length, uterine CSA and ovarian volume. Ovarian volume was also greater in IPT than in IPA. Ovarian morphology was significantly different in patients (IPT, CPP, IPA) compared with age-matched controls, but none of the ovarian morphological appearances was exclusive to a single condition. IN CONCLUSION: (i) pelvic ultrasound parameters increase progressively from birth to maturity, but no clear cut-off values can be established between age ranges; (ii) pelvic ultrasound variables reach adult values during puberty, with differences in the timing that may reflect geographical variations; (iii) the multicystic ovarian appearance occurs just before the onset of puberty; (iv) pelvic ultrasonography cannot always differentiate clearly between different disturbances of puberty and therefore cannot supersede other observations and investigations in the evaluation of pubertal disorders; and (v) in this study we propose a more detailed pelvic ultrasound terminology that can avoid apparent confusion in defining ovarian ultrasound appearance.

Growth, insulin-like growth factor I (IGF-I), and IGF-binding proteins 1 and 3 in children with severe liver disease before and after liver transplantation: a longitudinal and cross-sectional study.

We aimed to study the growth and growth factors of children with liver disease before and after liver transplantation (LT). Three observation intervals: 1) before LT (preLT), 2) after LT on daily prednisone treatment (dP), and 3) on alternate day prednisone (adP). A longitudinal study (LS) involved 17 infants (9 male) aged 0.73-2.38 y at LT; mean (+/- SD) height (Ht) SD score (SDS) at LT was -2.02 (+/- 1.25). In a cross-sectional study, there were 123 children (73 male) aged 0.16-14.88 y (mean 3.72 y). IGF-I and IGF binding proteins (BP) 1 and 3 were measured at the same intervals. The results were, for LS, preLT height velocity (HV) SDS (X +/- SD -0.8+/-1.4) lower (p < 0.01) than adP-HV SDS (3.1+/-1.8) but not different from dP-HV SDS (-1.0+/-1.9). For the cross-sectional study, dP-Ht SDS (X+/-SD -1.94+/-1.31) lower (p < 0.001) than preLT-Ht SDS (-1.03+/-1.06) and adP-Ht SDS (-0.98+/-1.20). Parental target SDS was not different from adP-Ht SDS. (Similar observations were made in the LS.) The dP- sitting height (SH) and subischial leg length (SLL) SDS were significantly lower than both preLT- and adP-SH SDS and SLL SDS (p = 0.02 and 0.002, respectively). There was a significant improvement of head circumference SDS and arm circumference SDS from preLT to adP. The dP and adP IGF-I and IGF-BP3 levels were greater than preLT levels (p < 0.001); no differences were found between preLT, dP, and adP IGF-BP1 levels. We conclude that growth in children with liver disease does not improve after LT on dP, but catch-up growth is shown on adP, appearing to depend mainly on the clinical course and corticosteroid regimen. IGF-I and IGF-BP3 increment on dP (and sustained on adP) is possibly due to liver regeneration, in contrast with inhibition of body growth on dP, possibly due to central and peripheral effects of corticosteroid.

Loperamide test: a simple and highly specific screening test for hypercortisolism in children and adolescents.

The overnight dexamethasone (DXM) test can give false-positive results in a few conditions (e.g. stress, strenuous exercise, depression, anorexia, anxiety, anticonvulsive therapy) in diagnosing simple obesity and hypercortisolism (HC). The loperamide (LP; a peripheral opioid agonist) test has proven useful in such conditions in adults. Thirty-one obese subjects (age 10.0-19.7 y) were studied by both overnight DXM test and LP test (8 mg orally, samples for cortisol at 0, 90, 150, 180 and 210 min) on 2 separate days. LP suppressed cortisol (< or = 138 nmol l-1) at a dose of 0.1 mg kg-1 bw (half the minimum recommended dose for the drug's antidiarrhoea effect) in 14 subjects who had normal urinary (< 4970 nmol l-1) and serum (< 552 nmol l-1) cortisol, in the absence of signs and symptoms of HC (group A). The DXM test failed to suppress cortisol in three subjects in group A, two of whom were on anticonvulsive treatment. The LP test suppressed cortisol in all of 13 subjects with elevated urinary and/or serum cortisol and/or with signs or symptoms of HC (but in whom HC was subsequently excluded on clinical grounds) (group B), while the DXM test failed to suppress cortisol in three subjects of this group. One of these was under anticonvulsive treatment and one suffered from anxiety and depression. In four patients with Cushing's syndrome (group C) neither DXM nor LP could suppress cortisol levels. Therefore, the sensitivity was 100% for both DXM and LP, while the specificity was 84% for DXM and 100% for LP. No side-effects were observed with either drug. In conclusion, LP is a useful alternative to DXM in those particular conditions that can affect its specificity in children.