De Lange syndrome: subjective and objective comparison of the classical and mild phenotypes

Neurobehavioral and developmental profiles: genotype-phenotype correlations in individuals with Cornelia de Lange syndrome

BACKGROUND

Cornelia de Lange (CdLS) is a rare genetic disorder that affects most body systems. Variants in multiple genes including NIPBL and SMC1A, can cause the syndrome. To date, literature on genotype-phenotype associations in individuals with CdLS is extremely limited, although studies suggest some differences in clinical phenotype severity across variants. This study aimed to examine and compare neurobehavioral differences and developmental variability across CdLS genes, specifically NIPBL and SMC1A, and identify genotype-phenotype correlations.

PARTICIPANTS AND METHODS

This patient-reported outcomes study included accessing data from the Coordination of Rare Diseases registry at Sanford. Parents of a total of 26 children/adults with CdLS and a known variant in NIPBL (Mean age = 20.46 years, SD = 11.21) and 12 with a known variant in SMC1A (Mean age = 11.08 years, SD = 9.04) completed a series of questionnaires regarding their child's developmental history. This included attainment of common language and motor milestones, intervention history, and behavior functioning. Developmental history and reported behavior regulation difficulties were compared across variant groups.

RESULTS

Overall, individuals with a pathogenic variant in NIPBL or SMC1A were similarly delayed across motor and language milestones with about 70% not using phrase speech and 30-50% not walking by 5 years of age. However, those with NIPBL variants showed more severity in behavioral phenotype, namely with more repetitive behaviors, tantrums, and withdrawn behaviors. In addition, these individuals were more likely than those with SMC1A variants to demonstrate self-injurious behaviors, and anxiety. Both groups yielded a similar proportion of participants who participated in speech and occupational therapy, however those with SMC1A variants were more likely to engage in physical therapy. Both clinical groups report low rate of communicative or assistive device use despite a large proportion of participants never mastering single word or sentence use.

CONCLUSIONS

Study results are consistent with recent investigations highlighting more severe behavioral phenotype, particularly autistic features, anxiety, and behavior regulation challenges, among those with NIPBL variants albeit comparable developmental milestones. Both groups endorsed very elevated attention problems. Findings highlight importance of early interventions, including behavioral health services.

Clinical study and genetic analysis of Cornelia de Lange syndrome caused by a novel MAU2 gene variant in a Chinese boy

BACKGROUND

Cornelia de Lange syndrome (CdLS) is mainly characterized by specific facial features, growth retardation, and bone deformities. Seven genes reportedly cause CdLS. Recent research has reported that loss-of-function variants affecting MAU2, which encodes a regulator of the cohesin complex, can cause CdLS. Thus far, only one MAU2-CdLS case has been reported worldwide.

METHODS

We detected a novel variant in MAU2 gene, NM_015329, c.526C>T (p.Arg176Trp) in a Chinese patient with CdLS, constructed a plasmid for in vitro transcriptional and protein level analysis, and analyzed the interaction between the MAU2/NIPBL complex using molecular dynamics (MD).

RESULTS

The results showed that the level of the exogenous MAU2 mutant protein was significantly reduced compared with that of the exogenous wild-type protein. However, MD analysis predicted an increased binding free energy between the MAU2 and NIPBL proteins that may impact the structural stability of the complex.

CONCLUSION

We investigated a MAU2-CdLS case in a Chinese family, which strengthens the association between MAU2 variants and CdLS phenotypes. We therefore propose that MAU2 be included in the CdLS gene screening list.

History and highlights of the teratological collection in the Narrenturm, Vienna (Austria)

The collection of the Narrenturm in Vienna houses and maintains more than 50,000 objects including approximately 1200 teratological specimens; making it one of the biggest collections of specimens from human origin in Europe. The existence of this magnificent collection-representing an important resource for dysmorphology research, mostly awaiting contemporary diagnoses-is not widely known in the scientific community. Here, we show that the Narrenturm harbors a wealth of specimens with (exceptionally) rare congenital anomalies. These museums can be seen as physical repositories of human malformation, covering hundreds of years of dedicated collecting and preserving, thereby creating unique settings that can be used to expand our knowledge of developmental conditions that have to be preserved for future generations of scientists.

[Interpretation of the first international consensus for Cornelia de Lange syndrome]

Cornelia de Lange syndrome (CdLS) is a genetic syndrome with severe neurodevelopmental disorders as the main manifestation. Its clinical manifestations included mental retardation, typical facial features, intrauterine and postnatal developmental delay, and deformity in multiple organs and systems, with an incidence rate of about 1/10000 to 1/30000. International CdLS Consensus Group was established in 2017 and issued the first international consensus on CdLS, i.e., "Diagnosis and management of Cornelia de Lange syndrome: first international consensus statement", in July 2018. Being developed through a modified Delphi consensus process, this consensus provides guidance on the diagnosis and management of children with CdLS. This article gives an interpretation of this consensus, aiming to help clinicians with early identification, diagnosis, standard follow-up, and management of this disease.

De novo NIPBL Mutations in Vietnamese Patients with Cornelia de Lange Syndrome

Cornelia de Lange Syndrome (CdLS) is a rare congenital genetic disease causing abnormal unique facial phenotypes, several defects in organs and body parts, and mental disorder or intellectual disorder traits. Main causes of CdLS have been reported as variants in cohesin complex genes, in which mutations in the NIPBL gene have been estimated to account for up to 80%. Our study included three Vietnamese patients with typical CdLS phenotypes. Whole exome sequencing revealed two known heterozygous mutations c.6697G>A (p.Val2233Met) and c.2602C>T (p.Arg868X), and a novel heterozygous mutation c.4504delG (p.Val1502fsX87) in the NIPBL gene of the three patients. In silico analyses of the identified mutations predicted possible damaging and truncating effects on the NIPBL protein. Inherited analyses in the patients' families showed that all of the mutations are de novo. Our results lead a definitive diagnosis of patients with CdLS and expand the spectrum of mutations in the NIPBL gene. These findings also confirm whole exome sequencing is an efficient tool for genetic screening of CdLS.

Mixed Phenotype of Langer-Giedion's and Cornelia de Lange's Syndromes in an 8q23.3-q24.1 Microdeletion without TRPS1 Deletion

Langer-Giedion's syndrome (LGS) or trichorhinophalangeal syndrome type II (TRPS II; MIM:150230) is a contiguous gene deletion syndrome caused by the haploinsufficiency of the TRPS1 and EXT1 genes. Cornelia de Lange's syndrome (CdLS) is a genetically heterogeneous dysmorphic syndrome where heterozygous mutations of RAD21 gene have been associated with a mild clinical presentation (CDLS type 4; MIM: 614701). We report a female patient with a 2.3-Mb interstitial deletion at 8q23.3-q24.1 encompassing EXT1 and RAD21 genes but not TRPS1 . Clinical findings in this patient are correlated with a mixed phenotype of LGS and CdLS type 4.

Soft Tissue Facial Angles in Individuals with Ectodermal Dysplasia: A Three-Dimensional Noninvasive Study

Objective

To supply quantitative information about the facial soft tissues of patients with hypohidrotic ectodermal dysplasia.

Design

Prospective assessment.

Setting

National meetings of hypohidrotic ectodermal dysplasia patients and families.

Patients and Main Outcome Measures

Facial and mandibular corpus convexities in the horizontal plane; facial convexity in the sagittal plane; interlabial, naso-labial, nasal convexity, and left and right soft tissue gonial angles were calculated from the three-dimensional coordinates of 11 soft tissue facial landmarks obtained in 18 male and 17 female hypohidrotic ectodermal dysplasia patients aged 3 to 41 years and in 504 reference healthy individuals. In addition, z-scores were computed and the patients were grouped by cluster analysis.

Results

Male and female z-scores did not differ. In the pooled group, facial convexities in the horizontal and sagittal planes were significantly (Student's t, p < .01) increased (flatter) in hypohidrotic ectodermal dysplasia patients, compared with normal controls. The naso-labial angle was significantly reduced (more acute). Upper and lower facial convexity and mandibular corpus convexity in the horizontal plane deviated less from the norm with increasing age. Facial convexity in the horizontal and sagittal planes, soft tissue gonial angles, and naso-labial and interlabial angles deviated less from the norm with increasing number of teeth present in the mouth. Cluster analysis identified three homogeneous groups, all characterized by a peculiar facial phenotype. Modifications in facial convexity and gonial and interlabial angles differentiated each cluster.

Conclusions

Patients with hypohidrotic ectodermal dysplasia had flatter faces in the horizontal and sagittal planes than normal controls had. Cluster analysis revealed patterned differences in facial phenotype.

Determining the frequency of morphological characteristics in a sample of Brazilian children

OBJECTIVE

To establish the frequency of 82 morphological features in a sample of Brazilian children (between 3 and 13 years old), to understand the influence of age, gender, and ethnicity.

METHODS

This was a cross-sectional study that evaluated 239 children with typical development (between 3 and 13 years old) regarding the presence of 82 morphological characteristics. A previously described protocol, based on the London Dysmorphology Database, was applied to evaluate the sample. This protocol was culturally adapted to Brazilian Portuguese.

RESULTS

The frequency of 82 morphological characteristics was established in the sample; of 82 characteristics, 50% were considered morphological anomalies (frequency less than 4%). At least 25% of the sample presented more than one minor morphological anomaly. Age was shown to influence the frequency of the following morphological characteristics: widow's peak, prominent antihelix, prominent upper lip, irregular or crowded teeth, and clinodactyly, but had no influence on the frequency of minor morphological anomalies. Gender influenced dysplastic ears and attached earlobe, but had no influence on the frequency of minor morphological anomalies; ethnicity showed influence on camptodactyly and prominent antihelix. A statistically significant divergence was observed regarding 43 of the 73 morphological characteristics that could be compared with literature data (58.9%).

CONCLUSIONS

The study determined the frequency of 82 morphological characteristics in 239 children with typical development. Age was the variable that showed more influence on the frequency of morphological characteristics, and comparison with literature data showed that the frequency depends on variables such as age and ethnicity.

A new prognostic index of severity of intellectual disabilities in Cornelia de Lange syndrome

Cornelia de Lange syndrome is a well-known multiple congenital anomalies/intellectual disability syndrome with genetic heterogeneity and wide clinical variability, regarding the severity of both the intellectual disabilities and the physical features, not completely explained by the genotype-phenotype correlations known to date. The aim of the study was the identification of prognostic features, ascertainable precociously in the patient's life, of a better intellectual outcome and the development of a new prognostic index of severity of intellectual disability in CdLS patients. In 66 italian CdLS patients aged 8 years or more, we evaluated the association of the degree of intellectual disability with various clinical parameters ascertainable before 6 months of life and with the molecular data by the application of cumulative regression logistic model. Based on these results and on the previously known genotype-phenotype correlations, we selected seven parameters to be used in a multivariate cumulative regression logistic model to develop a prognostic index of severity of intellectual disability. The probability of a mild ID increases with the reducing final score less than two, the probability of a severe ID increases with the increasing final score more than three. This prognostic index allows to define, precociously in the life of a baby, the probability of a better or worse intellectual outcome in CdLS patients. © 2016 Wiley Periodicals, Inc.

Cornelia de Lange syndrome due to mosaic NIPBL mutation: antenatal presentation with sacrococcygeal teratoma

A male infant at 36 weeks gestation was born by section. At 20 weeks of gestation, congenital diaphragmatic hernia and sacrococcygeal teratoma had been seen on ultrasound. At birth, the infant had features suggestive of Cornelia de Lange syndrome (CdLS). He remained hypoxic despite aggressive ventilatory manoeuvres and was palliated. At postmortem, the lungs were hypoplastic. In CdLS, mutations in NIPBL are found in around 50% of cases. Mutation analysis, including multiplex ligation dependent probe amplification of the NIPBL gene from the DNA extracted from peripheral blood lymphocytes was negative, but microarray comparative genomic hybridisation on DNA from skin fibroblast showed a 0.13Mb deletion on chromosome 5p13. The deleted region includes exons 42-47 of the NIPBL gene. It is important to perform NIBPL mutation analysis on DNA from more than one tissue when testing for CdLS.

People with intellectual disability: what do we know about adulthood and life expectancy?

Increases in the life expectancy of people with Intellectual Disability have followed similar trends to those found in the general population. With the exception of people with severe and multiple disabilities or Down syndrome, the life expectancy of this group now closely approximates with that of the general population. Middle and old age, which until 30 years ago were not recognized in this population, are now important parts of the life course of these individuals. Older adults with Intellectual Disabilities form a small, but significant and growing proportion of older people in the community. How these persons grow older and how symptoms and complications of the underlying cause of the Intellectual Disability will influence their life expectancy is of the utmost importance.

Aesthetic and functional management of a patient with Cornelia de Lange syndrome

Cornelia de Lange syndrome is a syndrome of multiple congenital anomalies. The genetic and molecular bases of these lesions are not clear. It is divided into three types based on the severity of the anomaly. Dental findings revealed contracted maxilla, malaligned teeth, multiple impacted and missing teeth. This article describes the successful management of upper central incisor with lateral opening in the apical third on the mesial surface of the root along with aesthetic and functional rehabilitation.

Investigation of autistic features among individuals with mild to moderate Cornelia de Lange syndrome

Cornelia de Lange syndrome (CdLS) is a congenital disorder characterized by distinctive facial features, growth retardation, limb abnormalities, intellectual disability, and behavioral problems. Autism has been reported to occur frequently in CdLS, but the frequency of autism in individuals with the milder CdLS phenotype is not well studied. We investigated autistic features by using a screening tool and a diagnostic interview in 49 individuals with the mild to moderate phenotype from a CdLS research database at the Children's Hospital of Philadelphia. The Social Communication Questionnaire (SCQ), a screening instrument for autistic disorder, was completed for all individuals. For individuals who screened positive and a subset of those that screened negative, the Autism Diagnostic Interview-Revised (ADI-R) was administered. Autistic symptom severity was not significantly different by gender, age groups, and genotypes. There was a significant correlation between higher levels of adaptive functioning and lower scores of autistic symptoms. The estimated prevalence of significant autistic features by ADI-R criteria was 43% in our cohort of individuals with the mild to moderate CdLS phenotype, which suggests that prevalence of autistic disorder may be higher than previously described among individuals with mild to moderate phenotype of CdLS. Clinicians who take care of individuals with CdLS should have a high index of suspicion for autistic features, and refer for further evaluation when these features are present in order to expedite appropriate intervention.

NIPBL rearrangements in Cornelia de Lange syndrome: evidence for replicative mechanism and genotype-phenotype correlation

PURPOSE

Cornelia de Lange syndrome (CdLS) is a multisystem congenital anomaly disorder characterized by mental retardation, limb abnormalities, distinctive facial features, and hirsutism. Mutations in three genes involved in sister chromatid cohesion, NIPBL, SMC1A, and SMC3, account for ~55% of CdLS cases. The molecular etiology of a significant fraction of CdLS cases remains unknown. We hypothesized that large genomic rearrangements of cohesin complex subunit genes may play a role in the molecular etiology of this disorder.

METHODS

Custom high-resolution oligonucleotide array comparative genomic hybridization analyses interrogating candidate cohesin genes and breakpoint junction sequencing of identified genomic variants were performed.

RESULTS

Of the 162 patients with CdLS, for whom mutations in known CdLS genes were previously negative by sequencing, deletions containing NIPBL exons were observed in 7 subjects (~5%). Breakpoint sequences in five patients implicated microhomology-mediated replicative mechanisms-such as serial replication slippage and fork stalling and template switching/microhomology-mediated break-induced replication-as a potential predominant contributor to these copy number variations. Most deletions are predicted to result in haploinsufficiency due to heterozygous loss-of-function mutations; such mutations may result in a more severe CdLS phenotype.

CONCLUSION

Our findings suggest a potential clinical utility to testing for copy number variations involving NIPBL when clinically diagnosed CdLS cases are mutation-negative by DNA-sequencing studies.

Identification of a novel de novo mutation in the NIPBL gene in an Iranian patient with Cornelia de Lange syndrome: A case report

BACKGROUND

Cornelia de Lange syndrome is characterized by dysmorphic facial features, hirsutism, severe growth and developmental delay. Germline mutations in the NIPBL gene with an autosomal dominant pattern and in the SMC1A gene with an X-linked pattern have been identified in Cornelia de Lange syndrome.

CASE PRESENTATION

A two-month-old Iranian boy who showed multiple congenital anomalies was referred to the genetic center of a welfare organization in southwest Iran. He was the second child of a non-consanguineous marriage, born after full term with normal delivery. His birth weight was 3110 g, his length was 46 cm and his head circumference was 30 cm. Both parents were clinically asymptomatic, with no positive history of any deformity in their respective families.

CONCLUSIONS

Sequencing of the NIPBL gene from our patient revealed a single-base deletion of thymidine in exon 10 (c.516delT). This mutation presumably results in premature termination at codon 526. We did not observe this mutation in the parents of our patient with Cornelia de Lange syndrome. The results presented here enlarge the spectrum of NIPBL gene mutations associated with Cornelia de Lange syndrome by identifying a novel de novo mutation in an Iranian patient with Cornelia de Lange syndrome and further support the hypothesis that NIPBL mutations are disease-causing mutations leading to Cornelia de Lange syndrome.

The role of anthropometric measurements in nasal surgery and research: a systematic review

BACKGROUND

Anthropometric measurements of the nose provide objective data about the size and shape of the nose. Data of average nasal anthropometric values for various ethnic groups is promoted to be of great importance in planning aesthetic nasal surgery, but there may be fundamental problems with this approach.

OBJECTIVE OF REVIEW

To collate existing knowledge on nasal anthropometry and, determine its value to the nasal surgeon, in planning aesthetic nasal surgery and in research.

SEARCH STRATEGY

A structured search of PubMed was performed from 1 January 1973 to 31 December 2009 focussing on nasal anthropometry. The MeSH keywords used were nasal/nose, anthropometry/history/methods/measurements, aesthetic, surgery, nose, otorhinolaryngologic surgical procedures.

RESULTS

There is published literature on the average values of the nasal dimensions for various ethnic groups, to aid surgeons in planning improvements of the face. However the large overlap of anthropometric data between racial groups and the lack of any scientific basis for the concept of race means that the published data for racial groups is of little use in planning nasal surgery. Nasal anthropometry, however, helps to answer important clinical questions in research. It has established the role of primary rhinoplasty in patients with cleft lip nasal deformity. It serves as an objective tool to investigate whether reconstructive nasal septoplasty in the paediatric population has any deleterious effect on nasal growth. Anthropometry also helps in the characterisation of dysmorphic syndromes.

CONCLUSIONS

The published anthropometric data for racial groups is of little use in planning nasal surgery. Anthropometric measurements of the nose may help to answer important clinical questions in research on the effects of surgery on nasal and facial development.

Cornelia de Lange syndrome case due to genomic rearrangements including NIPBL

Cornelia de Lange syndrome (CdLS) is a rare multisystem congenital anomaly disorder characterized by growth and developmental delay, distinctive facial dysmorphism, limb malformations and multiple organ defects. Approximately 60-65% of the CdLS subjects have mutation in one of three cohesin proteins, a main regulator of cohesin-associated protein, NIPBL, and two components of the cohesin ring structure SMC1A and SMC3. A prominent role for cohesin is to control chromosome segregation during cell divisions. We have performed MLPA analysis in a group of 11 children with the CdLS but without identifiable point mutations in the NIPBL and SMC1A genes. In a single patient, we identified a large deletion encompassing exons 35 to 47 of the NIPBL gene. Our finding was validated by aCGH and further characterized by long-range PCR and DNA sequencing of the breakpoint junction.

Facial diagnosis of mild and variant CdLS: Insights from a dysmorphologist survey

Cornelia de Lange syndrome (CdLS) is a dominant disorder with classic severe forms and milder atypical variants. Central to making the diagnosis is identification of diagnostic facial features. With the recognition that patients with SMC1A and SMC3 mutations have milder, atypical features, we surveyed 65 dysmorphologists using facial photographs from 32 CdLS patients with the goals of (1) Illustrating examples of milder patients with SMC1A mutations and (2) Obtaining objective data to determine which facial features were useful and misleading in making a diagnosis of CdLS. Clinicians were surveyed whether the patient had CdLS or another diagnosis, the certainty of response and the clinical features used to support each response. Using only facial photographs, an average of 24 cases (75%) were accurately diagnosed per clinician. Correct diagnoses were made in 90% of classic CdLS and 87% of non-CdLS cases, however, only 54% of mild or variant CdLS were correctly diagnosed by respondents. We confirmed that CdLS is most accurately diagnosed in childhood and the diagnosis becomes increasingly difficult with age. This survey demonstrated that emphasis is placed on the eyebrows, nasal features, prominent upper lip and micrognathia. In addition, the presence of fuller, atypical eyebrows, a prominent nasal bridge and significant prognathism with age dissuaded survey takers from arriving at a diagnosis of CdLS in individuals with mild NIPBL and SMC1A mutations. This work underscores the difficulty in diagnosing patients with mild and variant CdLS and serves to objectively classify both useful and misleading features in the diagnosis of CdLS.

Cornelia de Lange syndrome, cohesin, and beyond

Cornelia de Lange syndrome (CdLS) (OMIM #122470, #300590 and #610759) is a dominant genetic disorder with multiple organ system abnormalities which is classically characterized by typical facial features, growth and mental retardation, upper limb defects, hirsutism, gastrointestinal and other visceral system involvement. Mutations in three cohesin proteins, a key regulator of cohesin, NIPBL, and two structural components of the cohesin ring SMC1A and SMC3, etiologically account for about 65% of individuals with CdLS. Cohesin controls faithful chromosome segregation during the mitotic and meiotic cell cycles. Multiple proteins in the cohesin pathway are also involved in additional fundamental biological events such as double-strand DNA break repair and long-range regulation of transcription. Moreover, chromosome instability was recently associated with defective sister chromatid cohesion in several cancer studies, and an increasing number of human developmental disorders is being reported to result from disruption of this pathway. Here, we will discuss the human disorders caused by alterations of cohesin function (termed 'cohesinopathies'), with an emphasis on the clinical manifestations of CdLS and mechanistic studies of the CdLS-related proteins.

Multiple organ system defects and transcriptional dysregulation in the Nipbl(+/-) mouse, a model of Cornelia de Lange Syndrome

Cornelia de Lange Syndrome (CdLS) is a multi-organ system birth defects disorder linked, in at least half of cases, to heterozygous mutations in the NIPBL gene. In animals and fungi, orthologs of NIPBL regulate cohesin, a complex of proteins that is essential for chromosome cohesion and is also implicated in DNA repair and transcriptional regulation. Mice heterozygous for a gene-trap mutation in Nipbl were produced and exhibited defects characteristic of CdLS, including small size, craniofacial anomalies, microbrachycephaly, heart defects, hearing abnormalities, delayed bone maturation, reduced body fat, behavioral disturbances, and high mortality (75–80%) during the first weeks of life. These phenotypes arose despite a decrease in Nipbl transcript levels of only ∼30%, implying extreme sensitivity of development to small changes in Nipbl activity. Gene expression profiling demonstrated that Nipbl deficiency leads to modest but significant transcriptional dysregulation of many genes. Expression changes at the protocadherin beta (Pcdhb) locus, as well as at other loci, support the view that NIPBL influences long-range chromosomal regulatory interactions. In addition, evidence is presented that reduced expression of genes involved in adipogenic differentiation may underlie the low amounts of body fat observed both in Nipbl+/− mice and in individuals with CdLS.

Cornelia de Lange Syndrome (CdLS) is a genetic disease marked by growth retardation, cognitive and neurological problems, and structural defects in many organ systems. The majority of CdLS cases are due to mutation of one copy of the Nipped B-like (NIPBL) gene, the product of which regulates a complex of chromosomal proteins called cohesin. How reduction of NIPBL function gives rise to pervasive developmental defects in CdLS is not understood, so a model of CdLS was developed by generating mice that carry one null allele of Nipbl. Developmental defects in these mice show remarkable similarity to those observed in individuals with CdLS, including small stature, craniofacial abnormalities, reduced body fat, behavioral disturbances, and high perinatal mortality. Molecular analysis of tissues and cells from Nipbl mutant mice provide the first evidence that the major role of Nipbl in the etiology of CdLS is to exert modest, but significant, effects on the expression of diverse sets of genes, some of which are located in characteristic arrangements along the DNA. Among affected genes is a set involved in the development of adipocytes, the cells that make and accumulate body fat, potentially explaining reductions in body fat accumulation commonly observed in individuals with CdLS.

Synophyrs, curly eyelashes and Ptyrigium colli in a girl with Desbuquois dysplasia: a case report and review of the literature

Introduction

Desbuquois dysplasia is a rare, but well described syndrome with remarkable clinical and radiographic variability ranging from mild skeletal involvement with normal intelligence to those with early fatal outcome.

Case presentation

Distinctive radiographic features of Desbuquois dysplasia-typical hand type have been documented in a 3-year-old girl. Synophyrs, curly eyelashes and ptyrigium colli were additional findings.

Conclusion

The phenotypic variability of Desbuquois syndrome might be an element of diagnostic confusion. However, distinctive radiographic features should urgently requiring attention and are virtually diagnostic. We report what might be the first clinical report of Desbuquois dysplasia from a consanguineous family in Austria. Unusual facial dysmorphism resembling Cornelia-De Lange syndrome and early patellar ossification were additional unreported features in connection with Desbuquois dysplasia.

Genomic duplication resulting in increased copy number of genes encoding the sister chromatid cohesion complex conveys clinical consequences distinct from Cornelia de Lange

BACKGROUND

Cornelia de Lange syndrome (CdLS) is a multisystem congenital anomaly disorder. Heterozygous point mutations in three genes (NIPBL, SMC3 and SMC1A), encoding components of the sister chromatid cohesion apparatus, are responsible for approximately 50-60% of CdLS cases. Recent studies have revealed a high degree of genomic rearrangements (for example, deletions and duplications) in the human genome, which result in gene copy number variations (CNVs). CNVs have been associated with a wide range of both Mendelian and complex traits including disease phenotypes such as Charcot-Marie-Tooth type 1A, Pelizaeus-Merzbacher, Parkinson, Alzheimer, autism and schizophrenia. Increased versus decreased copy number of the same gene can potentially cause either similar or different clinical features.

METHODS AND RESULTS

This study identified duplications on chromosomes 5 or X using genome wide array comparative genomic hybridisation (aCGH). The duplicated regions contain either the NIPBL or the SMC1A genes. Junction sequences analyses revealed the involvement of three genomic rearrangement mechanisms. The patients share some common features including mental retardation, developmental delay, sleep abnormalities, and craniofacial and limb defects. The systems affected are the same as in CdLS, but clinical manifestations are distinct from CdLS; particularly the absence of the CdLS facial gestalt.

CONCLUSIONS

The results confirm the notion that duplication CNV of genes can be a common mechanism for human genetic diseases. Defining the clinical consequences for a specific gene dosage alteration represents a new "reverse genomics" trend in medical genetics that is reciprocal to the traditional approach of delineation of the common clinical phenotype preceding the discovery of the genetic aetiology.

Cornelia de Lange syndrome (CdLS): prenatal and autopsy findings

Cornelia de Lange Syndrome (CdLS) is a multisystem disorder characterized by somatic defects and mental retardation. Prenatal diagnosis of this severe condition is difficult in view of the non-specific ultrasound abnormalities. We report three cases with prenatally suspected CdLS based on the ultrasound findings as well as low PAPP-A detected on first trimester screening in one case, and the results of the autopsy and the NIPBL gene mutation analysis.

Syndromale Formen geistiger Behinderung

Die geistige Behinderung bei syndromalen Krankheitsbildern kann sehr verschieden stark ausgeprägt sein. Auch können Betroffene mit dem gleichen Syndrom einen unterschiedlichen Schweregrad der geistigen Behinderung aufweisen. Die Diagnosestellung stellt eine große Herausforderung für den klinischen Genetiker dar, insbesondere wegen der unterschiedlichen phänotypischen Ausprägung. Neben einer exakten Erhebung der Familienanamnese und der körperlichen Befunde ist die Beachtung von Leitsymptomen wie Adipositas, Makrosomie, Mikrozephalie, prä- oder postnatalem Kleinwuchs oder spezifischer Fehlbildungsmuster hilfreich bei der klinischen Diagnostik. Die modernen zytogenetischen und molekularzytogenetischen Diagnostiken wie CGH-Array (CGH: „comparative genomic hybridization“) tragen dazu bei, eine ätiologische Klärung herbeizuführen und Krankheitsentitäten zu definieren.

Simultaneous analysis of the behavioural phenotype, physical factors, and parenting stress in people with Cornelia de Lange syndrome

BACKGROUND

Studies into the phenotype of rare genetic syndromes largely rely on bivariate analysis. The aim of this study was to describe the phenotype of Cornelia de Lange syndrome (CdLS) in depth by examining a large number of variables with varying measurement levels. Virtually the only suitable multivariate technique for this is categorical principal component analysis. The characteristics of the CdLS phenotype measured were also analysed in relation to parenting stress.

METHOD

Data for 37 children and adults with CdLS were collected. The type of gene mutation and relevant medical characteristics were measured. Information on adaptive functioning, behavioural problems, the presence of the autistic disorder and parenting stress were obtained through questionnaires and semi-structured interviews with the parents. Chronological age and gender were also included in the analysis.

RESULTS

All characteristics measured, except gender, were highly interrelated and there was much variability in the CdLS phenotype. Parents perceived more stress when their children were older, were lower functioning, had more behavioural problems, and if the autistic disorder was present. A new perspective was acquired on the relation between the gene mutation type and medical and behavioural characteristics. In contrast with earlier research the severity of medical characteristics did not appear a strong prognostic factor for the level of development.

CONCLUSION

Categorical principal component analysis proved particularly valuable for the description of this small group of participants given the large number of variables with different measurement levels. The success of the technique in the present study suggests that a similar approach to the characterisation of other rare genetic syndromes could prove extremely valuable. Given the high variability and interrelatedness of characteristics in CdLS persons, parents should be informed about this differentiated perspective.

Dental findings in Cornelia de Lange syndrome

Cornelia de Lange syndrome is a congenital disease, basically characterized by psychomotor retardation associated with a series of malformations, including mainly skeletal, craniofacial deformities together with gastrointestinal and cardiac malformations. There is no definitive biochemical or chromosomal marker for the prenatal diagnosis of this syndrome. We actually want to present the case of a 10-year-old patient, who was admitted to our clinic for dental pain. The patient had the symptoms of Cornelia de Lange syndrome. During the oral examination of this patient, the patient was found to have the typical symptoms of Cornelia de Lange syndrome, such as micrognathia and delayed eruption in conjunction with the symptoms of the Hutchinson's syndrome, which had never been reported before.

A newborn with Cornelia de Lange syndrome: a case report

Cornelia de Lange syndrome (CdLS) is a rarely seen multisystem developmental disorder syndrome characterized by facial dysmorphia (arched eyebrows, synophrys, depressed nasal bridge, long philtrum, down-turned angles of the mouth), upper-extremity malformations, hirsutism, cardiac defects, growth and cognitive retardation, and gastrointestinal abnormalities. The features of this disorder vary widely among affected individuals and range from relatively mild to severe. Early in life, the distinctive craniofacial features in mild de Lange syndrome may be indistinguishable from the severe (classical) phenotype. We present here a case of newborn with CdLs.

Cornelia de Lange syndrome: clinical review, diagnostic and scoring systems, and anticipatory guidance

Cornelia de Lange syndrome (CdLS), also known as Brachmann-de Lange syndrome, is a well-described multiple malformation syndrome typically involving proportionate small stature, developmental delay, specific facial features, major malformations (particularly the cardiac, gastrointestinal and musculoskeletal systems), and behavioral abnormalities. There is a broad spectrum of clinical involvement, with increasing recognition of a much milder phenotype than previously recognized. Significant progress has been made in recent years in the clinical and molecular delineation of CdLS, necessitating a revision of the diagnostic criteria, more inclusive of the milder cases. In addition, a scoring system of severity has been found to correlate with specific brain changes. Thus, a clinical overview and recommendations for anticipatory guidance are timely in aiding caretakers and professionals to individualize care decisions and maximize developmental potential for individuals with CdLS. These guidelines are derived from consensus based on collective experience of over 500 patients with CdLS, observations of the natural history in children, adolescents, and adults, a review of the literature, and contacts with national support organizations in North America and Europe.

Descriptive epidemiology of Cornelia de Lange syndrome in Europe

Cornelia de Lange syndrome (CdLS) is a multiple congenital anomaly/mental retardation syndrome consisting of characteristic dysmorphic features, microcephaly, hypertrichosis, upper limb defects, growth retardation, developmental delay, and a variety of associated malformations. We present a population-based epidemiological study of the classical form of CdLS. The data were extracted from the database of European Surveillance of Congenital Anomalies (EUROCAT) database, a European network of birth defect registries which follow a standard methodology. Based on 23 years of epidemiologic monitoring (8,558,346 births in the 1980-2002 period), we found the prevalence of the classical form of CdLS to be 1.24/100,000 births or 1:81,000 births and estimated the overall CdLS prevalence at 1.6-2.2/100,000. Live born children accounted for 91.5% (97/106) of cases, fetal deaths 2.8% (3/106), and terminations of pregnancy following prenatal diagnosis 5.7% (6/106). The most frequent associated congenital malformations were limb defects (73.1%), congenital heart defects (45.6%), central nervous system malformations (40.2%), and cleft palate (21.7%). In the last 11 years, as much as 68% of cases with major malformations were not detected by routine prenatal US. Live born infants with CdLS have a high first week survival (91.4%). All patients were sporadic. Maternal and paternal age did not seem to be risk factors for CdLS. Almost 70% of patients, born after the 37th week of gestation, weighed <or=2,500 g. Low birth weight correlated with a more severe phenotype. Severe limb anomalies were significantly more often present in males.

Cohesin and human disease

Cornelia de Lange syndrome (CdLS) is a dominant multisystem disorder caused by a disruption of cohesin function. The cohesin ring complex is composed of four protein subunits and more than 25 additional proteins involved in its regulation. The discovery that this complex also has a fundamental role in long-range regulation of transcription in Drosophila has shed light on the mechanism likely responsible for its role in development. In addition to the three cohesin proteins involved in CdLS, a second multisystem, recessively inherited, developmental disorder, Roberts-SC phocomelia, is caused by mutations in another regulator of the cohesin complex, ESCO2. Here we review the phenotypes of these disorders, collectively termed cohesinopathies, as well as the mechanism by which cohesin disruption likely causes these diseases.

Natural history of aging in Cornelia de Lange syndrome

Observations about the natural history of aging in Cornelia de Lange syndrome (CdLS) are made, based on 49 patients from a multidisciplinary clinic for adolescents and adults. The mean age was 17 years. Although most patients remain small, obesity may develop. Gastroesophageal reflux persists or worsens, and there are early long-term sequelae, including Barrett esophagus in 10%; other gastrointestinal findings include risk for volvulus, rumination, and chronic constipation. Submucous cleft palate was found in 14%, most undetected before our evaluation. Chronic sinusitis was noted in 39%, often with nasal polyps. Blepharitis improves with age; cataracts and detached retina may occur. Decreased bone density is observed, with occasional fractures. One quarter have leg length discrepancy and 39% scoliosis. Most females have delayed or irregular menses but normal gynecologic exams and pap smears. Benign prostatic hypertrophy occurred in one male prior to 40 years. The phenotype is variable, but there is a distinct pattern of facial changes with aging. Premature gray hair is frequent; two patients had cutis verticis gyrata. Behavioral issues and specific psychiatric diagnoses, including self-injury, anxiety, attention-deficit disorder, autistic features, depression, and obsessive-compulsive behavior, often worsen with age. This work presents some evidence for accelerated aging in CdLS. Of 53% with mutation analysis, 55% demonstrate a detectable mutation in NIPBL or SMC1A. Although no specific genotype-phenotype correlations have been firmly established, individuals with missense mutations in NIPBL and SMC1A appear milder than those with other mutations. Based on these observations, recommendations for clinical management of adults with CdLS are made.

Microcephaly syndromes

The objective of this article is to review microcephaly from a genetics point of view, especially with regard to the process of identification of syndromes in which small head circumference occurs. Microcephaly can be due to either genetic or environmental causes. It can be the only positive finding or may be part of a syndrome of congenital anomalies. The genetic etiology can be caused by autosomal dominant, autosomal recessive, or X-linked genes or various types of chromosome anomalies. Some of the gene mutations have been identified recently. Syndromic microcephaly is associated with a large number of conditions. Some can be diagnosed, or at least suspected, based on their characteristic facial dysmorphism, and others can be searched for using databases of genetic disorders.

Mutations in cohesin complex members SMC3 and SMC1A cause a mild variant of cornelia de Lange syndrome with predominant mental retardation

Mutations in the cohesin regulators NIPBL and ESCO2 are causative of the Cornelia de Lange syndrome (CdLS) and Roberts or SC phocomelia syndrome, respectively. Recently, mutations in the cohesin complex structural component SMC1A have been identified in two probands with features of CdLS. Here, we report the identification of a mutation in the gene encoding the complementary subunit of the cohesin heterodimer, SMC3, and 14 additional SMC1A mutations. All mutations are predicted to retain an open reading frame, and no truncating mutations were identified. Structural analysis of the mutant SMC3 and SMC1A proteins indicate that all are likely to produce functional cohesin complexes, but we posit that they may alter their chromosome binding dynamics. Our data indicate that SMC3 and SMC1A mutations (1) contribute to approximately 5% of cases of CdLS, (2) result in a consistently mild phenotype with absence of major structural anomalies typically associated with CdLS, and (3) in some instances, result in a phenotype that approaches that of apparently nonsyndromic mental retardation.

Large genomic rearrangements in NIPBL are infrequent in Cornelia de Lange syndrome

Cornelia de Lange Syndrome (CdLS) is a multiple congenital anomaly syndrome characterized by a distinctive facial appearance, malformations of the upper limbs, and delay in growth and development. Mutations in NIPBL are associated with CdLS in 27-56% of cases and have been reported as point mutations, small insertions and deletions in coding regions, regulatory regions and at splice junctions. All previous studies used PCR-based exon-scanning methodologies that do not allow detection of large genomic rearrangements. We studied the relative copy number of NIPBL exons in a series of 50 CdLS probands, negative for NIPBL mutations, by multiplex ligation-dependent probe amplification (MLPA). In a single patient, we found a 5.2 kb deletion encompassing exons 41-42 of NIPBL. Our studies indicate that large NIPBL rearrangements do occur in CdLS but are likely to be infrequent events.

A case of Cornelia de Lange syndrome from Sudan

Background

Brachmann de Lange syndrome (BDLS) is a multiple congenital anomaly syndrome characterized by a distinctive facial appearance, prenatal and postnatal growth deficiency, psychomotor delay, behavioral problems, and malformations of the upper extremities.

Case presentation

Here we present for the first time a case of BDLS from Sudan, a 7-month-old female infant, who was referred as a case of malnutrition. The patient was from a Sudanese western tribe. Clinical investigation showed that the child was a classical case of BDLS, but with some additional clinical findings not previously reported including crowded ribs and tied tongue.

Conclusion

Reporting BDLS cases of different ethnic backgrounds could add nuances to the phenotypic description of the syndrome and be helpful in diagnosis.

Comprehensive mutational analysis of a cohort of Swedish Cornelia de Lange syndrome patients

Cornelia de Lange syndrome (CdLS; OMIM 122470) is a rare multiple congenital anomaly/mental retardation syndrome characterized by distinctive dysmorphic facial features, severe growth and developmental delay and abnormalities of the upper limbs. About 50% of CdLS patients have been found to have heterozygous mutations in the NIPBL gene and a few cases were recently found to be caused by mutations in the X-linked SMC1L1 gene. We performed a mutation screening of all NIPBL coding exons by direct sequencing in 11 patients (nine sporadic and two familial cases) diagnosed with CdLS in Sweden and detected mutations in seven of the cases. All were de novo, and six of the mutations have not been previously described. Four patients without identifiable NIPBL mutations were subsequently subjected to multiplex ligation-dependent probe amplification analysis to exclude whole exon deletions/duplications of NIPBL. In addition, mutation analysis of the 5' untranslated region (5' UTR) of NIPBL was performed. Tiling resolution array comparative genomic hybridization analysis was carried out on these four patients to detect cryptic chromosome imbalances and in addition the boys were screened for SMC1L1 mutations. We found a de novo 9p duplication with a size of 0.6 Mb in one of the patients with a CdLS-like phenotype but no mutations were detected in SMC1L1. So far, two genes (NIPBL and SMC1L1) have been identified causing CdLS or CdLS-like phenotypes. However, in a considerable proportion of individuals demonstrating the CdLS phenotype, mutations in any of these two genes are not found and other potential loci harboring additional CdLS-causing genes should be considered.

Father-to-daughter transmission of Cornelia de Lange syndrome caused by a mutation in the 5' untranslated region of the NIPBL Gene

Cornelia de Lange syndrome (CdLS; also called Brachmann de Lange syndrome) is a developmental disorder characterized by typical facial dysmorphism, growth and mental retardation, microcephaly, and various malformations. Mutations in the NIPBL gene have been identified in approximately 40% of reported cases, suggesting either genetic heterogeneity or that some NIPBL mutations are not detected by current screening strategies. We screened a cohort of 21 patients with no previously identified NIPBL anomaly for mutations in the 5' untranslated region (5'UTR) and the proximal promoter of the NIPBL gene. We identified a heterozygous deletion-insertion mutation in exon 1, 321 nucleotides upstream of the translation initiation codon (c.-321_-320delCCinsA) in one affected girl and her mildly affected father. This mutation altered highly conserved nucleotides, was not found in 400 control alleles, arose de novo in the father, and cosegregated with the disease in the family. Using real-time quantitative PCR, we showed that NIPBL mRNA expression was lowered in patients' lymphocytes compared to control samples. Finally, we showed that, when subcloned into a luciferase reporter vector, the mutation leads to a significant reduction of reporter gene activity. Our results demonstrate that mutations in the 5' noncoding region of the NIPBL gene can be involved in the pathogenesis of CdLS. Mutations affecting this region of the gene might be associated with a milder phenotype.

Mutational and genotype-phenotype correlation analyses in 28 Polish patients with Cornelia de Lange syndrome

Cornelia de Lange syndrome (CdLS) is a multisystem congenital anomaly disorder characterized by prenatal and postnatal growth retardation, developmental delay, distinctive facial dysmorphism, limb malformations, and multiple organ defects. Mutations in the NIPBL gene have been discovered recently as a major etiology for this syndrome, and were detected in 27-56% of patients. Two groups have found significant differences in the severity or penetrance of some phenotypes between mutation positive and mutation negative patients. Different clinical features have also been described among patients with missense versus truncating mutations. In this study, we identified 13 NIPBL mutations in 28 unrelated Polish CdLS patients (46.4%), 11 were novel. Mutation positive patients were more severely affected in comparison to mutation negative individuals with respect to weight, height, and mean head circumference at birth, facial dysmorphism and speech impairment. Analyses of combined data from this and the two previous studies revealed that the degree of growth, developmental delay and limb defects showed significant differences between patients with and without mutations and between patients with missense and truncating mutations, whereas only a portion of these features differed significantly in any individual study. Furthermore, bioinformatic analyses of the NIPBL protein revealed several novel domains, which may give further clues about potential functions of this protein.

Construction and use of facial archetypes in anthropology and syndrome diagnosis

This paper describes the benefits of moving from recording simple Euclidian distances and angles between landmarks on the face to full three-dimensional visualisation and mapping using modern optical scanning techniques. Pilot experiments are reported on that strive to create facial archetypes which are accurately descriptive of various cohorts of people. Issues considered include variation amongst people of the same sex, age and population-of-origin. The study has discovered that very few people are needed to construct an "average" face, which is measurably indistinguishable from another average constructed using the faces of other people from within the group studied. This discovery has given the researchers confidence in the reliability of the archetypes which they have produced and this is important if such an analytical technique is to find application in discriminating between peoples on a population basis and in syndrome diagnosis.

Normal values for morphological abnormalities in school children

Clinical morphology has proven to be a strong tool in the delineation of many syndromes and a helpful instrument in molecular studies. Numerous studies have been performed investigating the prevalence of minor anomalies in various disorders; all concluding that minor anomalies can well be utilized as indicators of altered embryonic differentiation. However, for adequate evaluation, normal values for phenotypic abnormalities are essential. So far, only few studies on the frequency of phenotypic abnormalities in the normal population have been done having one thing in common: all were performed in newborn infants. We studied morphological characteristics in a group of 1,007 school children, representative for the Dutch population, through a body surface examination using detailed definitions for all morphological findings. The region of study and distribution of children over various school types was chosen in such a way that it represented the general Dutch population. The median age of the studied children was 11 years (range 8-14 years), sex ratio (M:F) was 0.93. Nine hundred twenty-three children were of Caucasian descent, 84 others of mixed ethnic backgrounds. The reliability of the examinations was tested by independent scoring of 111 children by two observers, showing a kappa score of 0.85. Normal values for the morphological findings are presented together with their age-adjusted classification. These normal values provide a valuable source for validation of classifications of phenotypic abnormalities, especially those that are depending on frequency, that is, minor anomalies and common variants. Furthermore, they will allow a proper evaluation of patterns of phenotypic abnormalities found in patient groups with specific disorders.

Genotype-phenotype correlations of 39 patients with Cornelia De Lange syndrome: the Dutch experience

BACKGROUND

Cornelia de Lange syndrome (CdLS) is a multiple congenital anomaly syndrome characterised by a distinctive facial appearance, prenatal and postnatal growth deficiency, psychomotor delay, behavioural problems, and malformations of the upper extremities. Recently mutations in NIPBL, the human homologue of the Drosophila Nipped-B gene, were found to cause CdLS. Mutations have been found in 39% of reported cases.

METHODS

Patients were enrolled in the study and classified into one of four groups based on clinical examination: classic, mild, possible, or definitively not CdLS. Three dimensional photography was taken of 20 subjects, and compared between groups. Behaviour was assessed with specific attention to autism. We searched for mutations in NIPBL and correlated genotype with phenotype.

RESULTS

: We found mutations in 56% of cases.

CONCLUSIONS

Truncating mutations were generally found to cause a more severe phenotype but this correlation was not absolute. Three dimensional facial imaging demonstrated the potential for classifying facial features. Behavioural problems were highly correlated with the level of adaptive functioning, and also included autism. No correlation of behaviour with the type of mutation was found.

Shox2-deficient mice exhibit a rare type of incomplete clefting of the secondary palate

The short stature homeobox gene SHOX is associated with idiopathic short stature in humans, as seen in Turner syndrome and Leri-Weill dyschondrosteosis, while little is known about its close relative SHOX2. We report the restricted expression of Shox2 in the anterior domain of the secondary palate in mice and humans. Shox2-/- mice develop an incomplete cleft that is confined to the anterior region of the palate, an extremely rare type of clefting in humans. The Shox2-/- palatal shelves initiate, grow and elevate normally, but the anterior region fails to contact and fuse at the midline, owing to altered cell proliferation and apoptosis, leading to incomplete clefting within the presumptive hard palate. Accompanied with these cellular alterations is an ectopic expression of Fgf10 and Fgfr2c in the anterior palatal mesenchyme of the mutants. Tissue recombination and bead implantation experiments revealed that signals from the anterior palatal epithelium are responsible for the restricted mesenchymal Shox2 expression. BMP activity is necessary but not sufficient for the induction of palatal Shox2 expression. Our results demonstrate an intrinsic requirement for Shox2 in palatogenesis, and support the idea that palatogenesis is differentially regulated along the anteroposterior axis. Furthermore, our results demonstrate that fusion of the posterior palate can occur independently of fusion in the anterior palate.

Soft tissue facial areas and volumes in subjects with Down syndrome

The objective of this study was to supply quantitative information about the facial soft-tissues of a group of subjects with Down syndrome. The three-dimensional coordinates of 28 soft-tissue facial landmarks were obtained by an electromechanic digitizer in 17 male and 11 female subjects with Down syndrome aged 12-45 years, and in 429 healthy individuals of the same age, ethnicity, and sex. From the landmarks, facial areas (eyes, ears, nose, and lips) and volumes (nose and lips) were calculated according to a geometrical model of face. Data were compared to those collected in the normal subjects by computing z-scores. Male and female z-scores were not significantly different. Most of the facial volumes were significantly (Student's t, P < 0.05) smaller in subjects with Down syndrome than in their normal controls. Ear areas were significantly reduced (mean z-scores in males -2.07 right, -1.9 left; in females -2.11 right, -2.21 left), as well as nasal surface area (mean z-score -1.53 in males, -2.45 in females). In women, age and some z-scores were significantly correlated (P < 0.05): upper lip volume (r = 0.714), left and right eye area (r = 0.635, right; 0.604, left), nasal area (r = 0.603): with increasing age, the negative values of the z-scores approached the 0 value of the reference population. In the pooled sample, age and the z-score of the total lip area were significantly correlated (r = 0.423): increasing age corresponded to a larger z-score value. The method allowed a simple, low cost, fast, and noninvasive examination of the subjects, and provided a quantitative assessment of the deviation from the norm.

Anomalies of the kidney and urinary tract are common in de Lange syndrome

Sixty-one patients affected by de Lange syndrome underwent a careful renal and urological evaluation including family and personal history, physical examination, urinalysis, renal tract ultrasonography, and serum creatinine. A voiding cystourethrography was performed in patients with urinary tract infections, in patients with renal ectopy, and in patients with small kidneys. Structural anomalies of the kidney and urinary tract were detected either by ultrasound or voiding cystourethrography in 25 patients (41%): absent or poor corticomedullary differentiation (N = 8; 13%), pelvic dilation (N = 6; 10%), vesicoureteral reflux (N = 5; 8%), small kidney (N = 3; 5%), isolated renal cyst (N = 3; 5%), and renal ectopia (N = 2; 3%). Renal function was normal in 52 patients (85%) but reduced in 9 patients (15%) with renal tract abnormalities. Overt proteinuria was disclosed in three patients with impaired renal function.

A giant novel gene undergoing extensive alternative splicing is severed by a Cornelia de Lange-associated translocation breakpoint at 3q26.3

Cornelia de Lange syndrome (CdLS) is a rare developmental malformation syndrome characterised by mental handicap, growth retardation, distinctive facial features and limb reduction defects. The vast majority of CdLS cases are sporadic. We carried out a high density bacterial artificial chromosome (BAC) microarray comparative genome hybridisation screen but no evidence was found for a consistent pattern of microdeletion/microduplication. As an alternative, we focused on identifying chromosomal regions spanning associated translocation breakpoints. We prioritised the distal 3q region because of the occurrence, in a classical CdLS patient, of a de novo balanced translocation with a breakpoint at 3q26.3 and of reports of phenotypic overlap between cases of mild CdLS and individuals trisomic for the 3q26-q27 region. We show that the 3q26.3 breakpoint severs a previously uncharacterised giant gene, NAALADL2, containing at least 32 exons spanning 1.37 Mb. Northern blot analysis identified up to six different transcripts in the 1-10 kb range with strongest expression in kidney and placenta; embryonic expression was largely confined to duodenal and stomach endoderm, mesonephros, metanephros and pancreas. Transcript analysis identified extensive alternative splicing leading to multiple 5' and 3' untranslated regions and variable coding sequences. Multiple protein isoforms were defined by different N-terminal regions (with at least four alternative initiating methionine codons), and by differential protein truncation/use of alternative C-terminal sequences attributable to alternative splicing/polyadenylation. Outside the N-terminal regions, the predicted proteins showed significant homology to N-acetylated alpha-linked acidic dipeptidase and transferrin receptors. Mutation screening of NAALADL2 in a panel of CdLS patient DNA samples failed to identify patient-specific mutations. We discuss the possibility that the 3q26.3 translocation could nevertheless contribute to pathogenesis.