Expanding the clinical spectrum of the 'HDAC8-phenotype' - implications for molecular diagnostics, counseling and risk prediction.

Cornelia de Lange syndrome (CdLS) is a clinically heterogeneous disorder characterized by typical facial dysmorphism, cognitive impairment and multiple congenital anomalies. Approximately 75% of patients carry a variant in one of the five cohesin-related genes NIPBL, SMC1A, SMC3, RAD21 and HDAC8. Herein we report on the clinical and molecular characterization of 11 patients carrying 10 distinct variants in HDAC8. Given the high number of variants identified so far, we advise sequencing of HDAC8 as an indispensable part of the routine molecular diagnostic for patients with CdLS or CdLS-overlapping features. The phenotype of our patients is very broad, whereas males tend to be more severely affected than females, who instead often present with less canonical CdLS features. The extensive clinical variability observed in the heterozygous females might be at least partially associated with a completely skewed X-inactivation, observed in seven out of eight female patients. Our cohort also includes two affected siblings whose unaffected mother was found to be mosaic for the causative mutation inherited to both affected children. This further supports the urgent need for an integration of highly sensitive sequencing technology to allow an appropriate molecular diagnostic, genetic counseling and risk prediction.

A short history of the initial discovery of the SHOX gene.

Already in 1981 Davis had reported that small Yp terminal deletion resulted in short stature and, basing his findings on Davis's results, on the results of other publications, and on his own observations that Xp terminal deletions normally result in short stature regardless of the breakpoints, in 1993 Ogata suggested that a growth gene was located in the pseudoautosomal region (PAR) and that haploinsufficiency of the growth gene actually caused short stature as a dominant phenotype. Rao et al. in 1997 cloned a gene from the distal part of the PAR and gave it the name SHOX for "short stature homeobox-containing" gene. SHOX is expressed from an inactive X chromosome and an active X and a normal Y chromosome, indicating that SHOX produces the dosage effect in sex chromosome aberrations. In the same year, both Ellison and Rao demonstrated that SHOX is most clearly expressed in bone marrow fibroblasts, thus suggesting that SHOX has a particular importance in bone growth and maturation.

Mandibuloacral dysplasia type A in childhood.

Mandibuloacral dysplasia type A (MADA) is characterized by growth retardation, postnatal onset of craniofacial anomalies with mandibular hypoplasia, progressive acral osteolysis, and skin changes including mottled pigmentation, skin atrophy, and lipodystrophy. Owing to its slowly progressive course, the syndrome has been recognized in adults, and pediatric case reports are scarce. We present the clinical case of two children in whom the diagnosis of MADA was made at an unusually early age. A 5-year-old boy presented with ocular proptosis, thin nose, and short and bulbous distal phalanges of fingers. A 4-year-old girl presented with round face and chubby cheeks, thin nose, bulbous fingertips, and type A lipodystrophy. In both, a skeletal survey showed wormian bones, thin clavicles, short distal phalanges of fingers and toes with acro-osteolysis. Both children were found to be homozygous for the recurrent missense mutation, c.1580G>A, (p.R527H) in exon 9 of the LMNA gene. Thus, the phenotype of MADA can be manifest in preschool age; diagnosis may be suggested by short and bulbous fingertips, facial features, and lipodystrophy, supported by the finding of acral osteolysis, and confirmed by mutation analysis.

Mowat-Wilson syndrome: facial phenotype changing with age: study of 19 Italian patients and review of the literature.

Mowat-Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of the ZEB2 gene, and characterized by typical face, moderate-to-severe mental retardation, epilepsy, Hirschsprung disease, and multiple congenital anomalies, including genital anomalies (particularly hypospadias in males), congenital heart defects, agenesis of the corpus callosum, and eye defects. Since the first delineation by Mowat et al. [Mowat et al. (1998); J Med Genet 35:617-623], approximately 179 patients with ZEB2 mutations, deletions or cytogenetic abnormalities have been reported primarily from Europe, Australia and the United States. Genetic defects include chromosome 2q21-q23 microdeletions (or different chromosome rearrangements) in few patients, and ZEB2 mutations in most. We report on clinical and genetic data from 19 Italian patients, diagnosed within the last 5 years, including six previously published, and compare them with patients already reported. The main purpose of this review is to underline a highly consistent phenotype and to highlight the phenotypic evolution occurring with age, particularly of the facial characteristics. The prevalence of MWS is likely to be underestimated. Knowledge of the phenotypic spectrum of MWS and of its changing phenotype with age can improve the detection rate of this condition.

Massive hemobilia and papillomatosis of the gallbladder in metachromatic leukodystrophy: a life-threatening condition.

Polyposis of the gallbladder is rare during childhood. This condition can be associated with three other conditions: metachromatic leukodystrophy, Peutz-Jeghers' syndrome, and pancreaticobiliary maljunction. We report the case of a child with hemobilia in metachromatic leukodystrophy, which rendered cholecystectomy necessary. Macroscopically, the gallbladder measured 4.6 cm in length and showed an opaque serous surface and focal brown petechiae. Moreover, a yellow polypoid lesion of 2 cm in diameter and a diffuse thickening of the fundus wall were observed. Many reports describe the importance of the association of gallbladder papillomatosis with metachromatic leukodystrophy, but only three cases presented with massive intestinal bleeding, such as our young patient had. It is thus imperative that this life-threatening condition should be well known.

Reconstruction of larval origins based on genetic relatedness and biophysical modeling.

The assessment of the mechanisms and patterns of larval connectivity between geographically separated populations leads to a better understanding of benthic marine population dynamics, especially in commercially valuable species. This study investigated for the first time the fine-scale temporal genetic variability of new settlers and their origins in a benthic marine organism with one of the longest pelagic larval phases, the Caribbean spiny lobster (Panulirus argus). We genotyped newly settled postlarvae in the Florida Keys and adults of spiny lobster from the Florida Keys and throughout the Caribbean Sea. We identified strong larval connectivity between Dominican Republic, Belize, Nicaragua, the Florida Keys, and West-Florida. The larval dispersal modeling suggests that Florida's lobster population could receive recruits from within and from other areas outside its state and national maritime boundaries. The genetic analyses refine the oceanographic model indicating that the connectivity patterns described could also result from unknown parental populations sourcing adults and postlarvae in different spawning seasons to the Florida Keys. We discuss the importance of small temporal scales to identify patterns in larval export. Our findings are significant on two levels. From the larval dispersal perspective, genetic results and biophysical modeling identify patterns of gene flow enhancing persistence of local populations. From an economic and fishery perspective, P. argus is the most important commercial species in the Caribbean and our results inform how considering larval source and sink dynamics across international boundaries could improve management plans at local, national, and regional levels.

Holt-Oram syndrome associated with anomalies of the feet.

Holt-Oram syndrome (HOS) (OMIM 142900) is characterized by upper-extremity malformations involving the radial, thenar, or carpal bones and a personal and/or family history of congenital heart defects (CHDs). It is inherited in an autosomal dominant manner. The TBX5 gene located on chromosome 12 (12q24.1) is the only gene currently known to be associated with HOS and is associated with variable phenotypes. We report on the clinical and molecular characterization of a HOS family with three affected individuals and a novel mutation (Lys88ter). We discuss genotype-phenotype correlations, the presence of foot anomalies in one affected individual, and the role of atypical features in HOS differential diagnosis.

Prematurity, ventricular septal defect and dysmorphisms are independent predictors of pathogenic copy number variants: a retrospective study on array-CGH results and phenotypical features of 293 children with neurodevelopmental disorders and/or multiple congenital anomalies.

BACKGROUND: Since 2010, array-CGH (aCGH) has been the first-tier test in the diagnostic approach of children with neurodevelopmental disorders (NDD) or multiple congenital anomalies (MCA) of unknown origin. Its broad application led to the detection of numerous variants of uncertain clinical significance (VOUS). How to appropriately interpret aCGH results represents a challenge for the clinician. METHOD: We present a retrospective study on 293 patients with age range 1 month - 29 years (median 7 years) with NDD and/or MCA and/or dysmorphisms, investigated through aCGH between 2005 and 2016. The aim of the study was to analyze clinical and molecular cytogenetic data in order to identify what elements could be useful to interpret unknown or poorly described aberrations. Comparison of phenotype and cytogenetic characteristics through univariate analysis and multivariate logistic regression was performed. RESULTS: Copy number variations (CNVs) with a frequency < 1% were detected in 225 patients of the total sample, while 68 patients presented only variants with higher frequency (heterozygous deletions or amplification) and were considered to have negative aCGH. Proved pathogenic CNVs were detected in 70 patients (20.6%). Delayed psychomotor development, intellectual disability, intrauterine growth retardation (IUGR), prematurity, congenital heart disease, cerebral malformations and dysmorphisms correlated to reported pathogenic CNVs. Prematurity, ventricular septal defect and dysmorphisms remained significant predictors of pathogenic CNVs in the multivariate logistic model whereas abnormal EEG and limb dysmorphisms were mainly detected in the group with likely pathogenic VOUS. A flow-chart regarding the care for patients with NDD and/or MCA and/or dysmorphisms and the interpretation of aCGH has been made on the basis of the data inferred from this study and literature. CONCLUSION: Our work contributes to make the investigative process of CNVs more informative and suggests possible directions in aCGH interpretation and phenotype correlation.

Anophthalmos with limb anomalies (Waardenburg opththalmo-acromelic syndrome): report of a new Italian case with renal anomaly and review.

Anophthalmos with limb anomalies (Waardenburg Opththalmo-Acromelic Syndrome) is a very rare autosomal recessive multiple congenital anomaly syndrome, first described by Waardenburg et al. in 1961 (MIM 206920). It is characterized by mono or more often bilateral anophthalmia/microphthalmia and foot malformations, which can be observed in 91% of the patients. The most common anomaly of the feet is the presence of four toes. The hands are affected bilaterally in 77% of the cases. The most characteristic anomaly is the synostosis of the fourth and fifth metacarpals. To date, 33 cases from 19 families have been reported. We present an Italian case of anophthalmia with limb anomalies and a renal malformation, which has never been described in the literature.

MRI and neurological findings in macrocephaly-cutis marmorata telangiectatica congenita syndrome: report of ten cases and review of the literature.

MRI and neurological findings in macrocephaly-cutis marmorata telangiectatica congenita syndrome: report of ten cases and review of the literature: We describe the clinical history and magnetic resonance imaging (MRI) findings in 10 children with the Macrocephaly-Cutis Marmorata Telangiectatica Congenita syndrome (M-CMTC--MIM 602501). This syndrome has recently been delineated within the general group of patients with Cutis Marmorata Telangiectatica (CMTC) as a distinct and easily recognisable entity. In contrast to most children with CMTC, patients with M-CMTC syndrome have a high risk of neurological abnormalities, such as hydrocephalus, megalencephaly, developmental delay and mental retardation. An MRI scan showed structural cerebral abnormalities in all of our patients, including megalencephaly, asymmetry of the cerebral hemispheres and abnormally increased signal of white matter. Seven patients also had Chiari type I malformation. Reviewing all reported cases, we propose appropriate surveillance for known complications.

Neurofibromatosis type 1 and precocious puberty.

Since neurofibromatosis type 1 (NF1) is a well known cause of precocious puberty (PP), we reviewed 412 NF1 pediatric patients to evaluate the prevalence of PP, the association with optic pathway tumors (OPT), and other clinical, auxological and hormonal data. Thirty-one of 412 patients had OPT (7.5%), 10/412 PP (2.4%), and in seven of these PP was associated with OPT (7/31, 22.6%). OPT in patients with PP involved the chiasm in four patients, and the optic nerves alone in three patients. The age at the onset of puberty (or better at diagnosis) ranged from 5.2 to 7.5 yr in girls (n=6) and from 7.9 to 8.9 yr in boys (n=4). LHRH agonist therapy was used in only three children because in the others the predicted height at diagnosis was good, treatment was refused or the patients were referred to us too late. The three treated patients attained a final height within the familial range. In the untreated patients the progression of puberty was not too rapid and final height was slightly below the genetic target in four patients; however, three patients had a final height markedly below the familial range. In conclusion, the prevalence of PP is increased in children with NF1, and frequently but not exclusively is associated with OPT. Moreover, sexual precocity does not seem to be necessarily bound to chiasmatic OPT. Treatment seems to be useful in the children with younger age at the onset of puberty or with a progressive decline in predicted final height.

Growth and pubertal disorders in neurofibromatosis type 1.

The first textbook of Pediatric Endocrinology in the early 1950s reported an association of neurofibromatosis type 1 (NF1) and precocious puberty (PP) and/or short stature. Recent studies have indicated that children with NF1 grow normally until puberty; thereafter height velocity and relative height (SDS or percentiles) decreases with respect to healthy peers, reaching a mean adult height close to the 25th percentile for the general population. Moreover, the percentage of patients with true short stature (<3rd percentile) increases from childhood (5%) to late puberty (20-30% in literature, 18% in our study), and final height is significantly below the genetic target and predicted adult height calculated just before or at the beginning of puberty. Finally, among the shortest patients (<10th percentile) there is a high incidence of severe complications, such as CNS tumors, huge plexiform neurofibromas and severe scoliosis. Precocious puberty is a frequent complication of NF1, and occurs mainly in association with optic pathway tumors (OPT); however, occasionally it has been reported in the absence of optic gliomas, probably with a similar incidence as in the general population. GnRH agonist therapy must be decided individually as in some patients further growth could be normal and/or treatment would not improve final height. In the presence of early pubertal signs, an OPT must be ruled out. In addition to PP, delayed puberty has been frequently reported in NF1. In a study of 123 girls with NF1, we found that the mean age at menarche (13.0 +/- 1.9 yr) was later than in their mothers (12.7 +/- 1.4 yr) and in the general population (12.4 +/- 1.2 yr; p <0.05), with a very high incidence of delayed menarche (>2 SD): 16% vs 6.8% (mothers) vs 3.4% (controls) (p <0.01). In conclusion, growth and puberty present unusual patterns in NF1, often with true pathological findings increasing medical and psychological problems.

Reproductive outcomes in a population exposed long-term to inorganic selenium via drinking water.

Despite being an essential element in mammals and lower animals at very low doses, selenium is recognized as a teratogen and a growth-inhibiting substance in several animal species. Some inorganic selenium compounds have also been shown to be mutagenic and pro-oxidant: however, very little is known about their effects on human reproduction. Between 1972 and 1988, a few thousand residents in the municipality of Reggio Emilia, northern Italy, were accidentally exposed to drinking water with unusually high levels of inorganic selenium (selenate), range 7-9 microg/l, through a local public water supply system. We found no deleterious effect on overall body weight and length of newborns and stillborns delivered by 18 women previously exposed to high-selenium tapwater. Rates of spontaneous abortions, however, were increased slightly (RR = 1.73; 95% CI = 0.62-4.80), compared with rates among unexposed women from the same municipality. From 1980 through 1988 the prevalence of congenital malformations at birth among the exposed population was similar to that expected, but estimates were imprecise owing to small numbers. Results do not suggest marked effects on human reproduction from chronic exposure to selenate in drinking water at < 10 microg/l.

Marden-Walker syndrome: case report, nosologic discussion and aspects of counseling.

The Marden-Walker syndrome is characterized by a mask-like face with blepharophimosis, micrognathia, cleft or high-arched palate, low-set ears, congenital joint contractures, decreased muscular mass, failure to thrive and psychomotor retardation. We report a boy with a phenotype mostly resembling the condition named Marden-Walker syndrome, with many of the criteria proposed for diagnosing this particular phenotype. In addition he had hypoplastic corpus callosum, cerebellar vermis hypoplasia, enlarged cisterna magna and vertebral abnormalities. During pregnancy there were reduced fetal movements. In the present patient the fetal hypokinesia sequence, due to central nervous system malformation, is most compatible with the diagnosis of Marden-Walker syndrome. The etiology is probably heterogeneous, but the possibility of autosomal recessive inheritance should be considered in genetic counseling.

Oculo-auriculo-vertebral spectrum in Klinefelter syndrome.

We report a boy with classical 47,XXY Klinefelter syndrome (KS) and oculo-auriculo-vertebral spectrum (OAV). Two patients with KS and OAV were reported previously. Also, the combination of bilateral aplasia of the mandibular ramus and condyle and KS has been documented. The present observation supports the view that the cause of hemifacial microsomia appears heterogeneous and that OAV may be part of the spectrum of craniofacial anomalies associated with KS.

22q11.2 Distal Deletion Syndrome: Description of a New Case with Truncus Arteriosus Type 2 and Review.

22q11.2 deletion syndrome is mainly characterized by conotruncal congenital heart defects, velopharyngeal insufficiency, hypocalcemia and a characteristic craniofacial appearance. The etiology in the majority of patients is a 3-Mb recurrent deletion in region 22q11.2. Nevertheless, recently some cases of infrequent deletions with various sizes have been reported with a different phenotype. We report on a patient with congenital heart disease (truncus arteriosus type 2) in whom a de novo 1.3-Mb 22q11.2 deletion was detected by array comparative genomic hybridization. The deletion described corresponds to an atypical and distal deletion which spans low copy repeat (LCR) 4 and is associated with breakpoint sites that do not correspond to known LCRs of 22q11.2. We examine the clinical phenotype of our case and compare our findings with those published in the literature. The most prevalent clinical features in this type of deletion are a history of prematurity, pre-natal and post-natal growth retardation, slight facial dysmorphic features, microcephaly and developmental delay, with a speech defect in particular. These are clearly different from those found in the classic 22q11.2 deletion syndrome, and we believe that the main differential diagnosis should be with Silver-Russel syndrome. In our case we observe the cardiac phenotype with truncus arteriosus communis usually seen in the classic 22q11.2 deletion syndrome, and so far associated with the TBX1 gene. Significantly, however, TBX1 is not included in our patient's deletion. The possible roles of a position effect or other genes are discussed.