The clinical management of children with achondroplasia in Italy: results of clinician and parent/caregiver surveys.

PURPOSE: This study aimed to assess the real-world management of achondroplasia in Italy. METHODS: Two online surveys addressed to (1) parents/caregivers of individuals with achondroplasia and (2) Italian clinicians managing individuals with achondroplasia were conducted to assess real-world perspectives on achondroplasia management. Both surveys collected data on either patient or clinician demographics, details on diagnoses and referrals, disease complications, and views/experiences with limb lengthening surgery. RESULTS: In total, 42 parents/caregivers and 19 clinicians (from 18 hospitals) completed the surveys. According to parents/caregivers, achondroplasia diagnosis was most commonly made in the third trimester of gestation (55% of respondents), with a genetic test performed to confirm the diagnosis in all but one case. In contrast, the clinicians indicated that, while achondroplasia was typically suspected during the prenatal period (78%), diagnosis was more frequently confirmed postnatally (72%). Parents/caregivers reported that the greatest impact of achondroplasia-related complications occurred in their children between the ages of 2-5 years. The most significant complications were otitis, sleep apnoea, stenosis of the foramen magnum or pressure on the spinal cord, and hearing difficulties. Lengthening surgery had been presented as a treatment option to 92% of responding parents/caregivers, with 76% of clinicians viewing surgery favourably. Typically, clinicians' reasons for suggesting limb lengthening surgery were to improve patient quality of life, increase patient autonomy and self-acceptance, improve trunk-limb disproportion, short stature and walking, and ensure that all possible treatment options had been presented to the parents/caregivers. CONCLUSION: This survey provides insight into the real-world management of individuals with achondroplasia in Italy.

Allergooncology: an expanding research area.

The relationship between allergic diseases and cancer is a very controversial topic, widely discussed in the last decades. Many studies have demonstrated inverse association between allergy and cancer, but others have reached neutral conclusions or have indicated a positive role of allergy in the development of cancer. However, either inhibiting or favoring, many cells and molecules relevant in the allergic process play a role in tumorigenesis. On the one hand, activated immune cells, like classically activated macrophages "M1", activated dendritic cells, IL-33 and amphiregulin stimulated Innate Lymphoid Cells (ILC2), Th1, IFN-γ producing T CD8+ and B lymphocytes have inhibitory effects on tumorigenesis and tumor progression. On the other hand, tolerogenic immune cells, like alternatively activated macrophages "M2" (M2a, M2b and M2c), tolerogenic dendritic cells, ILC3, T regulatory and B regulatory lymphocytes, while inhibiting allergic sensitization and response, appear to favour carcinogenesis. Furthermore, M2 subtypes macrophages (M2a, M2b), IL-25 stimulated ILC2 and Th2 lymphocytes have a role both in inducing allergic reactions and in favouring cancer progression. In addition, mast cells, pivotal cells in allergy, have a different effect of tumorigenesis based on their location - they can promote cancer progression or inhibit it. Finally, eosinophils have shown a prevalent tumoricidal function mediated by α-defensins, TNF-α, granzymes A and IL-18. Better understanding the role of various cells on carcinogenesis can help in developing new strategies (diagnostic, therapeutic and of follow up) against tumor.

Say-Barber-Biesecker-Young-Simpson syndrome and Genitopatellar syndrome: Lumping or splitting?

The Say-Barber-Biesecker-Young-Simpson variant of Ohdo syndrome (SBBYSS) and Genitopatellar syndrome (GTPTS) are 2 rare but clinically well-described diseases caused by de novo heterozygous sequence variants in the KAT6B gene. Both phenotypes are characterized by significant global developmental delay/intellectual disability, hypotonia, genital abnormalities, and patellar hypoplasia/agenesis. In addition, congenital heart defects, dental abnormalities, hearing loss, and thyroid anomalies are common to both phenotypes. This broad clinical overlap led some authors to propose the concept of KAT6B spectrum disorders. On the other hand, some clinical features could help to differentiate the 2 disorders. Furthermore, it is possible to establish a genotype-phenotype correlation when considering the position of the sequence variant along the gene, supporting the notion of the 2 disorders as really distinct entities.

Diagnostic application of a capture based NGS test for the concurrent detection of variants in sequence and copy number as well as LOH.

Whole exome sequencing (WES) has made the identification of causative SNVs/InDels associated with rare Mendelian conditions increasingly accessible. Incorporation of softwares allowing CNVs detection into the WES bioinformatics pipelines may increase the diagnostic yield. However, no standard protocols for this analysis are so far available and CNVs in non-coding regions are totally missed by WES, in spite of their possible role in the regulation of the flanking genes expression. So, in a number of cases the diagnostic workflow contemplates an initial investigation by genomic arrays followed, in the negative cases, by WES. The opposite workflow may also be applied, according to the familial segregation of the disease. We show preliminary results for a diagnostic application of a single next generation sequencing panel permitting the concurrent detection of LOH and variations in sequences and copy number. This approach allowed us to highlight compound heterozygosity for a CNV and a sequence variant in a number of cases, the duplication of a non-coding region responsible for sex reversal, and a whole-chromosome isodisomy causing reduction to homozygosity for a WFS1 variant. Moreover, the panel enabled us to detect deletions, duplications, and amplifications with sensitivity comparable to that of the most widely used array-CGH platforms.

SNORD116 deletions cause Prader-Willi syndrome with a mild phenotype and macrocephaly.

Prader-Willi syndrome is a complex condition caused by lack of expression of imprinted genes in the paternally derived region of chromosome 15 (15q11q13). A small number of patients with Prader-Willi phenotype have been discovered to have narrow deletions, not encompassing the whole critical region, but only the SNORD116 cluster, which includes genes codifying for small nucleolar RNAs. This kind of deletion usually is not detected by the classic DNA methylation analysis test. We present the case of a male patient with a mild Prader-Willi phenotype and a small deletion including SNORD116, diagnosed by methylation-sensitive multiplex ligation-dependent probe amplification (MLPA. The patient showed neonatal hypotonia, hyperphagia, obesity, central hypogonadism, hypothyroidism, strabismus. Stature and intellectual development are within the normal range. The presence of macrocephaly, observed in other cases of SNORD116 deletions as well, is uncommon for the classic phenotype of the syndrome.

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.

Clinical and molecular characterization of Rubinstein-Taybi syndrome patients carrying distinct novel mutations of the EP300 gene.

Rubinstein-Taybi syndrome (RSTS) is a rare congenital neurodevelopmental disorder characterized by postnatal growth deficiency, skeletal abnormalities, dysmorphic features and cognitive deficit. Mutations in two genes, CREBBP and EP300, encoding two homologous transcriptional co-activators, have been identified in ˜55% and ˜3-5% of affected individuals, respectively. To date, only eight EP300-mutated RSTS patients have been described and 12 additional mutations are reported in the database LOVD. In this study, EP300 analysis was performed on 33 CREBBP-negative RSTS patients leading to the identification of six unreported germline EP300 alterations comprising one deletion and five point mutations. All six patients showed a convincing, albeit mild, RSTS phenotype with minor skeletal anomalies, slight cognitive impairment and few major malformations. Beyond the expansion of the RSTS-EP300-mutated cohort, this study indicates that EP300-related RSTS cases occur more frequently than previously thought (˜8% vs 3-5%); furthermore, the characterization of novel EP300 mutations in RSTS patients will enhance the clinical practice and genotype-phenotype correlations.

Histone acetylation deficits in lymphoblastoid cell lines from patients with Rubinstein-Taybi syndrome.

BACKGROUND: Rubinstein-Taybi syndrome (RSTS) is a congenital neurodevelopmental disorder defined by postnatal growth deficiency, characteristic skeletal abnormalities and mental retardation and caused by mutations in the genes encoding for the transcriptional co-activators with intrinsic lysine acetyltransferase (KAT) activity CBP and p300. Previous studies have shown that neuronal histone acetylation is reduced in mouse models of RSTS. METHODS: The authors identified different mutations at the CREBBP locus and generated lymphoblastoid cell lines derived from nine patients with RSTS carrying distinct CREBBP mutations that illustrate different grades of the clinical severity in the spectrum of the syndrome. They next assessed whether histone acetylation levels were altered in these cell lines. RESULTS: The comparison of CREBBP-mutated RSTS cell lines with cell lines derived from patients with an unrelated mental retardation syndrome or healthy controls revealed significant deficits in histone acetylation, affecting primarily histone H2B and histone H2A. The most severe defects were observed in the lines carrying the whole deletion of the CREBBP gene and the truncating mutation, both leading to a haploinsufficiency state. Interestingly, this deficit was rescued by treatment with an inhibitor of histone deacetylases (HDACi). CONCLUSIONS: The authors' results extend to humans the seminal observations in RSTS mouse models and point to histone acetylation defects, mainly involving H2B and H2A, as relevant molecular markers of the disease.

Kounis Syndrome as First Manifestation of Allergic Sensitization.

Mast cells are abundant in the heart, among myocardial fibers, around coronary arteries, within arterial intima and intramural vessels, and in atherosclerotic plaques. Their mediators can be released during anaphylaxis and be responsible for acute coronary syndrome. This condition has been described as Kounis syndrome (KS). We report three cases of acute myocardial ischemia, which fulfill the definition for KS. In Cases 1 and 2, the association of intense chest pain with acute urticaria after an allergenic contact (wasp sting and betalactam antibiotic administration, respectively) was suspected to be an attack of angina related to an allergic reaction. No signs of an allergic reaction were observed in Case 3, but only the history of a wasp sting suggested its relationship to loss of consciousness and heart ischemia when hypersensitivity to venom was ascertained. These cases strongly recommend measurement of anaphylactic biomarkers, such as tryptase, during acute coronary syndromes to detect the possible involvement of an allergic reaction. Conversely, measurement of cardiac biomarkers during anaphylaxis, even without obvious signs of myocardial ischemia, might identify patients at risk of myocardial injury.

Archaeal elongation factor 1 beta is a dimer. Primary structure, molecular and biochemical properties.

The elongation factor 1 beta (EF-1 beta), that in eukarya and archaea promotes the replacement of GDP by GTP on the elongation factor 1 alpha x GDP complex, was purified to homogeneity from the thermoacidophilic archaeon Sulfolobus solfataricus (SsEF-1 beta). Its primary structure was established by sequenced Edman degradation of the entire protein or its proteolytic peptides. The molecular weight of SsEF-1 beta was estimated as about 10000 or 20000 under denaturing or native conditions respectively; this finding suggests that the native protein exists as a dimer. The peptide chain of SsEF-1 beta is much shorter than that of its eukaryotic analogues and homology is found only at their C-terminal region; no homology exists between SsEF-1 beta and eubacterial EF-Ts. At 50 degrees C, at a concentration of SsEF-1 beta 5-fold higher than that of SsEF-1 alpha x [3H]GDP the rate of the exchange of [3H]GDP for GTP becomes about 160-fold faster. An analysis of the values of the energetic parameters indicates that in the presence of SsEF-1 beta the GDP/GTP exchange is entropically favoured. At 100 degrees C the half-life of SsEF-1 beta is about 4 h.

Crystallization of a hyperthermophilic archaeal elongation factor 1 alpha.

Intact and fully active elongation factor aEF-1 alpha from the hyperthermophilic archaeon Sulfolobus solfataricus has been crystallized as a complex with GDP. Crystals were stable at temperatures below 8 degrees C and showed significant diffraction beyond 3.0 A. The orthorhombic lattice parameters were a = 62.9 A, b = 81.3 A, c = 115.6 A with one molecule per asymmetric unit.

Mosaic trisomy 17 in amniocytes: phenotypic outcome, tissue distribution, and uniparental disomy studies.

Mosaicism for trisomy 17 in amniocyte cultures is a rare finding, whilst postnatal cases are exceptional. In order to gain insight into the possible effects of the distribution of the trisomic line and of uniparental disomy (UPD) on embryofoetal development, we have performed follow-up clinical, cytogenetic and molecular investigations into three newly detected prenatal cases of trisomy 17 mosaicism identified in cultured amniotic fluid. In the first case, the pregnancy ended normally with the birth of a healthy girl, and analysis of newborn lymphocytes and of multiple extra-embryonic tissues was indicative of confined placental mosaicism. The second case was also associated with a normal pregnancy outcome and postnatal development, and only euploid cells were found in peripheral blood after birth. However, maternal isodisomy 17 consequent to a meiosis II error and loss of a chromosome 17 homologue was detected in peripheral lymphocytes postnatally. In the third case, pathological examination after termination of pregnancy showed growth retardation and minor dysmorphisms, and the trisomic line was detected in foetal skin fibroblasts. In addition, biparental derivation of chromosome 17 was demonstrated in the euploid lineage. These results, together with previously reported data, indicate that true amniotic trisomy 17 mosaicism is more commonly of extra-embryonic origin and associated with normal foetal development. Phenotypic consequences may arise when the trisomic line is present in foetal tissues. Case 2 also represents the first observation of maternal UPD involving chromosome 17; the absence of phenotypic anomalies in the child suggests that chromosome 17 is not likely to be subject to imprinting in maternal gametes.

Relevance of histidine-84 in the elongation factor Tu GTPase activity and in poly(Phe) synthesis: its substitution by glutamine and alanine.

Substitution of His-84 (-->Gln and -->Ala), a residue of the switch II region of E. coli elongation factor (EF) Tu, hardly affected the binding of GTP or GDP. The activity in poly(Phe) synthesis and GTP hydrolysis of EF-Tu H84Q were both reduced to about 35%, as compared to EF-Tu wt, whereas EF-Tu H84A was inactive in poly(Phe) synthesis but still showed a 10% residual GTPase activity. Phe-tRNAPhe exerted a similar inhibitory effect on the GTPase activity of EF-Tu wt and EF-Tu H84Q while abolishing that of EF-Tu H84A. Ribosomes enhanced the GTPase activity of EF-Tu H84Q, but not that of EF-Tu H84A, on which they even seemed to exert an inhibitory effect. The one-round GTP hydrolysis associated with the EF-TuH84Q-dependent binding of Phe-tRNAPhe to poly(U)-programmed ribosomes was less efficient than with EF-Tu wt. Kirromycin stimulated the GTPase activities of both mutants less than EF-Tu wt. The results of this work do not support a catalytic role of His-84 in the intrinsic GTPase of EF-Tu, but they emphasize the importance of its side-chain for polypeptide synthesis and GTP hydrolysis.

The site for GTP hydrolysis on the archaeal elongation factor 2 is unmasked by aliphatic alcohols.

An appropriate mixture of ethylene glycol and BaCl2 enhanced the otherwise very low intrinsic GTPase activity of the elongation factor 2 isolated from the archaeon Sulfolobus solfataricus (SsEF-2). The enzymatic activity became up to 300-fold higher than that of the SsEF-2 GTPase measured in the absence of any stimulator, but remained 20-fold lower than that stimulated by ribosome. The stimulatory effect of ethylene glycol/Ba2+ was attributed to the increased affinity for GTP, probably related to a conformational change occurring in a hydrophobic region near the catalytic site.

Topics in cancer risk assessment.

The estimation of carcinogenic risks from exposure to chemicals has become an integral part of the regulatory process in the United States within the past decade. With it have come considerable controversy and debate over the scientific merits and shortcomings of the methods and their impact on risk management decisions. In this paper we highlight selected topics of current interest in the debate. As an indication of the level of public concern, we note the major recent reports on risk assessment from the National Academy of Sciences and the U.S Environmental Protection Agency's proposed substantial revisions to its Guidelines for Carcinogen Risk Assessment. We identify and briefly frame several key scientific issues in cancer risk assessment, including the growing recognition of the importance of understanding the mode of action of carcinogenesis in experimental animals and in humans, the methodologies and challenges in quantitative extrapolation of cancer risks, and the question of how to assess and account for human variability in susceptibility to carcinogens. In addition, we discuss initiatives in progress that may fundamentally alter the carcinogenesis testing paradigm.

"Snail-like pelvis" chondrodysplasia: a further case report.

Chondrodysplasia with snail-like pelvis (Schnechenbecken dysplasia) is a rare distinct, lethal, short-limbed dwarfism. We describe the clinical and radiological features of a new case in an Italian family.

Effect of paternal age in achondroplasia, thanatophoric dysplasia, and osteogenesis imperfecta.

The paternal ages of nonfamilial cases of achondroplasia (AC) (n = 78), thanatophoric dysplasia (TD) (n = 64), and osteogenesis imperfecta (OI) (n = 106), were compared with those of matched controls, from an Italian Indagine Policentrica Italiana sulle Malformazioni Congenite and a South American Estudio Colaborativo Latinoamericano de Malformaciones Congénitas series. The degree of paternal age effect on the origin of these dominant mutations differed among the three conditions. Mean paternal age was highly elevated in AC, 36.30 +/- 6.74 years in the IPIMC, and 37.19 +/- 10.53 years in the ECLAMC; less consistently elevated in TD, 33.60 +/- 7.08 years in the IPIMC, and 36.41 +/- 9.38 years in the ECLAMC; and only slightly elevated in OI in the ECLAMC, 31.15 +/- 9.25 years, but not in the IPIMC, 32.26 +/- 6.07 years. Increased maternal age or birth order in these conditions disappeared when corrected for paternal age. Approximately 50% of AC and TD cases, and only 30% of OI cases, were born to fathers above age 35 years. For AC and TD, the increase in relative incidence with paternal age fitted an exponential curve. The variability of paternal age effect in these new mutations could be due, among other reasons, to the high proportion of germ-line mosaicism in OI parents, or to the localization of the AC gene, mapped to the 4p16.3 region, in the neighborhood of an unstable DNA area.

Novel findings in a patient with Weaver or a Weaver-like syndrome.

We report on a young male patient with an overgrowth syndrome, who had normal birth weight. He had a number of manifestations typical of the Weaver syndrome (WS), such as advanced bone age, peculiar craniofacial appearance, and camptodactyly. He also showed severe mental and speech retardation and demineralisation of the bones of the hands and feet. The latter can be considered as unreported manifestations of WS, or the patient could represent an example of a new WS-like syndrome.

CFC syndrome: report on three additional cases.

We describe three patients, originating from three different Italian localities, affected by the cardio-facio-cutaneous (CFC) syndrome. In addition to a varying degree of mental retardation, these patients present characteristics consisting of a peculiar face with bitemporal frontal constriction and other anomalies involving the eyes, nose, ears, hair, skin, and heart that are consistent with this diagnosis.

Six additional cases of the KBG syndrome: clinical reports and outline of the diagnostic criteria.

A diagnosis of KBG syndrome was made in six unrelated patients. They presented with slight mental retardation, macrodontia, and skeletal abnormalities. Microcephaly, short stature, facial anomalies, and syndactylies were also noted. The diagnostic criteria of the KBG syndrome are discussed.