Novel inherited CDX2 variant segregating in a family with diverse congenital malformations of the genitourinary system

Anorectal malformations (ARMs) constitute a group of congenital defects of the gastrointestinal and urogenital systems. They affect males and females, with an estimated worldwide prevalence of 1 in 5000 live births. These malformations are clinically heterogeneous and can be part of a syndromic presentation (syndromic ARM) or as a nonsyndromic entity (nonsyndromic ARM). Despite the well-recognized heritability of nonsyndromic ARM, the genetic etiology in most patients is unknown. In this study, we describe three siblings with diverse congenital anomalies of the genitourinary system, anemia, delayed milestones, and skeletal anomalies. Genome sequencing identified a novel, paternally inherited heterozygous Caudal type Homeobox 2 (CDX2) variant (c.722A > G (p.Glu241Gly)), that was present in all three affected siblings. The variant identified in this family is absent from population databases and predicted to be damaging by most in silico pathogenicity tools. So far, only two other reports implicate variants in CDX2 with ARMs. Remarkably, the individuals described in these studies had similar clinical phenotypes and genetic alterations in CDX2 CDX2 encodes a transcription factor and is considered the master regulator of gastrointestinal development. This variant maps to the homeobox domain of the encoded protein, which is critical for interaction with DNA targets. Our finding provides a potential molecular diagnosis for this family's condition and supports the role of CDX2 in anorectal anomalies. It also highlights the clinical heterogeneity and variable penetrance of ARM predisposition variants, another well-documented phenomenon. Finally, it underscores the diagnostic utility of genomic profiling of ARMs to identify the genetic etiology of these defects.

[Analysis of SALL1 gene variant in a boy with Townes-Brocks syndrome without anal atresia]

OBJECTIVE

To explore the genetic basis for a child presented with renal failure and multi-cystic dysplastic kidney without anal atresia.

METHODS

Peripheral blood sample of the child and his parents were collected and subjected to whole exome sequencing. Candidate variant was verified by Sanger sequencing.

RESULTS

The 40-day-old infant had presented with vomiting brown matter in a 7 days neonate and was transferred for kidney failure. Clinical examination has discovered renal failure, polycystic renal dysplasia, congenital hypothyroidism, bilateral thumb polydactyly, sensorineural hearing loss and preauricular dermatophyte. Genetic testing revealed that he has harbored a previously unreported c.824delT, p.L275Yfs*10 frameshift variant of SALL1 gene, which was confirmed by Sanger sequencing as de novo.

CONCLUSION

The patient was diagnosed with Townes-Brocks syndrome due to the novel de novo variant of SALL1 gene. Townes-Brocks syndrome without anal atresia is rare. Above finding has also enriched the mutational spectrum of the SALL1 gene.

MED12-Related (Neuro)Developmental Disorders: A Question of Causality

MED12 is a member of the Mediator complex that is involved in the regulation of transcription. Missense variants in MED12 cause FG syndrome, Lujan-Fryns syndrome, and Ohdo syndrome, as well as non-syndromic intellectual disability (ID) in hemizygous males. Recently, female patients with de novo missense variants and de novo protein truncating variants in MED12 were described, resulting in a clinical spectrum centered around ID and Hardikar syndrome without ID. The missense variants are found throughout MED12, whether they are inherited in hemizygous males or de novo in females. They can result in syndromic or nonsyndromic ID. The de novo nonsense variants resulting in Hardikar syndrome that is characterized by facial clefting, pigmentary retinopathy, biliary anomalies, and intestinal malrotation, are found more N-terminally, whereas the more C-terminally positioned variants are de novo protein truncating variants that cause a severe, syndromic phenotype consisting of ID, facial dysmorphism, short stature, skeletal abnormalities, feeding difficulties, and variable other abnormalities. This broad range of distinct phenotypes calls for a method to distinguish between pathogenic and non-pathogenic variants in MED12. We propose an isogenic iNeuron model to establish the unique gene expression patterns that are associated with the specific MED12 variants. The discovery of these patterns would help in future diagnostics and determine the causality of the MED12 variants.

UBR7 functions with UBR5 in the Notch signaling pathway and is involved in a neurodevelopmental syndrome with epilepsy, ptosis, and hypothyroidism

The ubiquitin-proteasome system facilitates the degradation of unstable or damaged proteins. UBR1-7, which are members of hundreds of E3 ubiquitin ligases, recognize and regulate the half-life of specific proteins on the basis of their N-terminal sequences ("N-end rule"). In seven individuals with intellectual disability, epilepsy, ptosis, hypothyroidism, and genital anomalies, we uncovered bi-allelic variants in UBR7. Their phenotype differs significantly from that of Johanson-Blizzard syndrome (JBS), which is caused by bi-allelic variants in UBR1, notably by the presence of epilepsy and the absence of exocrine pancreatic insufficiency and hypoplasia of nasal alae. While the mechanistic etiology of JBS remains uncertain, mutation of both Ubr1 and Ubr2 in the mouse or of the C. elegans UBR5 ortholog results in Notch signaling defects. Consistent with a potential role in Notch signaling, C. elegans ubr-7 expression partially overlaps with that of ubr-5, including in neurons, as well as the distal tip cell that plays a crucial role in signaling to germline stem cells via the Notch signaling pathway. Analysis of ubr-5 and ubr-7 single mutants and double mutants revealed genetic interactions with the Notch receptor gene glp-1 that influenced development and embryo formation. Collectively, our findings further implicate the UBR protein family and the Notch signaling pathway in a neurodevelopmental syndrome with epilepsy, ptosis, and hypothyroidism that differs from JBS. Further studies exploring a potential role in histone regulation are warranted given clinical overlap with KAT6B disorders and the interaction of UBR7 and UBR5 with histones.

Helicase-inactivating BRIP1 mutation yields Fanconi anemia with microcephaly and other congenital abnormalities

Fanconi anemia is a genetically and phenotypically heterogeneous disorder characterized by congenital anomalies, bone marrow failure, cancer, and sensitivity of chromosomes to DNA cross-linking agents. One of the 22 genes responsible for Fanconi anemia is BRIP1, in which biallelic truncating mutations lead to Fanconi anemia group J and monoallelic truncating mutations predispose to certain cancers. However, of the more than 1000 reported missense mutations in BRIP1, very few have been functionally characterized. We evaluated the functional consequence of BRIP1 p.R848H (c.2543G > A), which was homozygous in two cousins with low birth weight, microcephaly, upper limb abnormalities, and imperforate anus and for whom chromosome breakage analysis of patient cells revealed increased mitomycin C sensitivity. BRIP1 p.R848H alters a highly conserved residue in the catalytic DNA helicase domain. We show that BRIP1 p.R848H leads to a defect in helicase activity. Heterozygosity at this missense has been reported in multiple cancer patients but, in the absence of functional studies, classified as of unknown significance. Our results support that this mutation is pathogenic for Fanconi anemia in homozygotes and for increased cancer susceptibility in heterozygous carriers.

Trisomy 22 with long spina bifida occulta: A case report

INTRODUCTION

Complete non-mosaic trisomy 22 is a fatal chromosomal disorder that only few fetuses can survive over 12 weeks as reported. Prenatal sonographic findings combined with postnatal or postmortem discoveries showed characteristic multi-systematic anomalies.

PATIENT CONCERNS

The unborn baby of a 35-year-old pregnant woman was found to have several anomalies during a prenatal sonographic scan, including intrauterine growth retardation, ventricular septal defect, flat facial profile, and unclear bilateral kidney structures.

DIAGNOSES

The fetus was diagnosed as having complete non-mosaic trisomy 22 by chromosomal analysis.

INTERVENTIONS

The pregnancy was terminated at 24 weeks, and autopsy was permitted.

OUTCOMES

Postmortem examinations revealed additional long-sectional spina bifida occulta and imperforate anus.

CONCLUSIONS

This was the first time a case of spinal cord defect was reported in trisomy 22 fetuses. More attention should be paid to the spinal cord during sonographic examinations in trisomy 22 fetuses.

Genetic research and structural dysplasia assessment of anorectal malformations in neonatal male rats induced by di(n-butyl) phthalate

This study was the first to investigate the genetic abnormalities and structural dysplasia of anorectal malformations (ARMs) in male rats induced by di(n-butyl) phthalate (DBP). DBP was administered to timed-pregnant rats to establish the ARM rat model. The incidence of ARMs in male offspring was 39.5%. In neonatal period, decreased body weight and anogenital distance were observed. The general image and histological analysis of male offspring confirmed the presence of ARMs. Anatomical examination of the ARM male rats revealed the dysplasia in solid organs (heart-lung, liver, spleen, and kidney). The decreases of serum testosterone concentration and androgen receptor expression in terminal rectum were indicative of the antiandrogenic effects of DBP. Moreover, significant decreased mRNA expressions of these androgen-related genes such as sonic hedgehog, Gli2, Gli3, bone morphogenetic protein 4, Wnt5a, Hoxa13, Hoxd13, fibroblast growth factor 10, and fibroblast growth factor receptor 2 were found in terminal rectum of the ARM male pubs. These results demonstrated that development of ARM rats was impaired by maternal exposure to DBP. The antiandrogenic effects of DBP disturbing the androgen-related signaling networks might play an important role in the occurrence of ARMs.

TWO DIFFERENT MUTATIONS OF GL13 GENE IN TWO DIFFERENT SYNDROMES

Polydactyly is among comnion extremity abnormalities. Mutations of GLI3 gene have been reported commonly in Greig Cephalopolysyndactyly Syndrome (GCPS) and Pallister-Hall Syndrome (PHS). We have determined two different mutations of GLI3 gene in two different cases, one of which is with GCPS and the other one is with PHS. A deletion mutation was detected in the proband with GCPS and his mother. Otherwise, we found that, unlike the previously reported, the mutation c.2437C>T, p.Q813X which was detected in the GLI3 gene caused typical PHS. We are in thought of that our cases will contribute to understanding of phenotypic variability leading to GLI3 mutations.

Anorectal malformation: the etiological factors

Anorectal malformation (ARM) is a congenital anomaly commonly encountered in pediatric surgery practice. Although surgical procedures correct the anatomical anomalies, the post-operative bowel function is not universally satisfactory. The etiology of ARM remains unclear. In this review, we summarize the current understanding of the genetic and epigenetic factors contributing to the pathogenesis of ARM, based on published animal models, human genetics and epidemiological researches. Appreciation of these factors may be helpful in the management of ARM in the future.

Johanson-blizzard syndrome

We present clinical features and genetic diagnosis in an Indian infant diagnosed with Johanson- Blizzard syndrome. This is a rare, autosomal recessive genetic condition with multi-system involvement and a characteristic facies. Molecular genetic testing is important to confirm the clinical diagnosis and offer prenatal diagnosis in future pregnancies.

Anal atresia, abnormal genitalia, and absent thumb: congenital malformations associated with mosaic ring chromosome 13

Because of the deletion of a segment of the chromosome during the formation of a ring, several clinical findings may be associated with ring chromosomes. Ring chromosome 13 is one of such disorders in which the genotype-phenotype correlation is stronger by virtue of the accumulating literature. It can be associated with multiple congenital abnormalities and severe mental retardation. We report a case with mosaic ring chromosome 13 whose prenatal ultrasound revealed bilateral ventriculomegaly. Anal atresia, unidentifiable external genitalia, and an absent thumb were observed in the postmortem examination.

Clinical geneticists' views of VACTERL/VATER association

VACTERL association (sometimes termed "VATER association" depending on which component features are included) is typically defined by the presence of at least three of the following congenital malformations, which tend to statistically co-occur in affected individuals: Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, and Limb abnormalities. Although the clinical criteria for VACTERL association may appear to be straightforward, there is wide variability in the way clinical geneticists define the disorder and the genetic testing strategy they use when confronted with an affected patient. In order to describe this variability and determine the most commonly used definitions and testing modalities, we present the results of survey responses by 121 clinical geneticists. We discuss the results of the survey responses, provide a literature review and commentary from a group of physicians who are currently involved in clinical and laboratory-based research on VACTERL association, and offer an algorithm for genetic testing in patients with this association.

Partial monosomy 9p (9p22.2-->pter) and partial trisomy 18q (18q21.32-->qter) in a female infant with anorectal malformations

We report a female infant with a karyotype of 46,XX,der(9)t(9;18)(p22.2;q21.32)pat and the phenotypic features of craniofacial dysmorphisms, developmental delay, hypotonia, horizontal nystagmus, strabismus, congenital heart defects, clubfoot, and anorectal malformations with an anterior ectopic anus and a stenosed anal opening. Array comparative genomic hybridization revealed a 16.93-Mb deletion at 9p24.3-p22.2 encompassing the FREM1 gene and a 20.43-Mb duplication at 18q21.32-q23 encompassing the PIGN gene. We speculate that dual genome imbalances in FREMI at 9p22.3 and in PIGN at 18q21.3 are most likely responsible for the abnormal development of anorectum in this patient.

[Mutation analysis of methyl CpG-binding protein 2 gene(exon 3) in Hirschsprung disease and anorectal malformations]

OBJECTIVE

To explore the relationship between exon 3 mutation in the methyl CpG-binding protein 2 (MeCP2-E3) gene and Hirschsprung disease (HSCR) and anorectal malformations (ARMs).

METHODS

PCR and DNA sequencing were used to detect the mutation of MeCP2-E3 in 120 healthy controls, 120 HSCR, and 50 ARMs.

RESULTS

On sequencing, 45(37.5%) children with HSCR had basic replacement in MeCP2-E3, 12(10.0%) of them were homozygous mutation. Fourteen(28.0%) children with ARMs had basic replacement in MeCP2-E3, 4(8%) of them were homozygous mutation. There were no mutation in the control group.

CONCLUSIONS

Mutation of MeCP2-E3 is present in the peripheral blood of children with HSCR or ARMs, which may contribute to the development of Hirschsprung disease or anorectal malformations.

VACTERL/VATER Association

VACTERL/VATER association is typically defined by the presence of at least three of the following congenital malformations: vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities. In addition to these core component features, patients may also have other congenital anomalies. Although diagnostic criteria vary, the incidence is estimated at approximately 1 in 10,000 to 1 in 40,000 live-born infants. The condition is ascertained clinically by the presence of the above-mentioned malformations; importantly, there should be no clinical or laboratory-based evidence for the presence of one of the many similar conditions, as the differential diagnosis is relatively large. This differential diagnosis includes (but is not limited to) Baller-Gerold syndrome, CHARGE syndrome, Currarino syndrome, deletion 22q11.2 syndrome, Fanconi anemia, Feingold syndrome, Fryns syndrome, MURCS association, oculo-auriculo-vertebral syndrome, Opitz G/BBB syndrome, Pallister-Hall syndrome, Townes-Brocks syndrome, and VACTERL with hydrocephalus. Though there are hints regarding causation, the aetiology has been identified only in a small fraction of patients to date, likely due to factors such as a high degree of clinical and causal heterogeneity, the largely sporadic nature of the disorder, and the presence of many similar conditions. New genetic research methods offer promise that the causes of VACTERL association will be better defined in the relatively near future. Antenatal diagnosis can be challenging, as certain component features can be difficult to ascertain prior to birth. The management of patients with VACTERL/VATER association typically centers around surgical correction of the specific congenital anomalies (typically anal atresia, certain types of cardiac malformations, and/or tracheo-esophageal fistula) in the immediate postnatal period, followed by long-term medical management of sequelae of the congenital malformations. If optimal surgical correction is achievable, the prognosis can be relatively positive, though some patients will continue to be affected by their congenital malformations throughout life. Importantly, patients with VACTERL association do not tend to have neurocognitive impairment.

Parental risk factors and anorectal malformations: systematic review and meta-analysis

BACKGROUND

Anorectal malformations (ARM) are rare forms of congenital uro-rectal anomalies with largely unknown causes. Besides genetic factors, prenatal exposures of the parents to nicotine, alcohol, caffeine, illicit drugs, occupational hazards, overweight/obesity and diabetes mellitus are suspected as environmental risk factors.

METHODS

Relevant studies published until August 2010 were identified through systematic search in PubMed, EMBASE, ISI Web of Knowledge and the Cochrane Library databases. Furthermore, related and cross-referencing publications were reviewed. Pooled odds ratios (95% confidence intervals) were determined to quantify associations of maternal and paternal smoking, maternal alcohol consumption, underweight (body mass index [BMI] < 18.5), overweight (BMI 25-29.9), obesity (BMI ≥30) and maternal diabetes mellitus with ARM using meta-analyses.

RESULTS

22 studies that reported on the association between prenatal environmental risk factors and infants born with ARM were included in this review. These were conducted in the United States of America (n = 12), Spain (n = 2), Sweden (n = 2), the Netherlands (n = 2), Japan (n = 1), France (n = 1), Germany (n = 1) and Hungary (n = 1). However, only few of these studies reported on the same risk factors. Studies were heterogeneous with respect to case numbers, control types and adjustment for covariates. Consistently increased risks were observed for paternal smoking and maternal overweight, obesity and diabetes, but not for maternal smoking and alcohol consumption. In meta-analyses, pooled odds ratios (95% confidence intervals) for paternal smoking, maternal overweight, obesity, pre-gestational and gestational diabetes were 1.53 (1.04-2.26), 1.25 (1.07-1.47), 1.64 (1.35-2.00), 4.51 (2.55-7.97) and 1.81 (1.23-2.65), respectively.

CONCLUSION

Evidence on risk factors for ARM from epidemiological studies is still very limited. Nevertheless, the few available studies indicate paternal smoking and maternal overweight, obesity and diabetes to be associated with increased risks. Further, ideally large-scale multicentre and register-based studies are needed to clarify the role of key risk factors for the development of ARM.

Partial trisomy 10p12.33 and partial monosomy 13q32.1: case report and a literature review

We report on a preterm neonate with a deletion of the distal long arm of chromosome 13q32.1 and partial trisomy of the short arm of chromosome 10p12.33. The patient has intrauterine growth retardation, microphthalmia, macrocephaly, holoprosencephaly, patent ductus arteriosus, aortic isthmus hypoplasia, right renal agenesis, imperforate anus, ambiguous genitalia, pleural effusion and vertebral anomaly. Analysis using an oligonucleotide microarray (U-array Cyto6000 array platform (Human Genome build: hg 18) indicated that there was a partial trisomy of chromosome 10(19.5 Mb gain) involving 298 oligonucleotides from 10pter to 10p12.33, and a partial monosomy of chromosome 13(18.3 Mb deleted) involving 313 oligonucleotides from 13q32.1 to 13qter. This is the first report of a patient with partial trisomy 10p12.33 and partial monosomy 13q32.1.

Anorectal and urinary anomalies and aberrant retinoic acid metabolism in cytochrome P450 oxidoreductase deficiency

CONTEXT

Cytochrome P450 oxidoreductase (POR) is an electron donor for all microsomal P450 enzymes including CYP26 involved in inactivation of all-trans retinoic acid (atRA). Although previous studies in Por knockout mice suggest that atRA accumulation is relevant to various posterior organ abnormalities, a systematic analysis has not been performed for anorectal and urinary anomalies in patients with POR deficiency (PORD).

OBJECTIVE

To report the frequencies of anorectal and urinary anomalies and plasma atRA values in PORD patients.

PATIENTS

We studied 37 Japanese patients with PORD, consisting of 15 homozygotes for R457H (group A), 15 compound heterozygotes for R457H and one apparently null mutation (group B), and seven patients with other combinations of mutations (group C). Since R457H is a severe hypomorphic mutation, the residual POR function is predicted to be higher in group A than in group B.

RESULTS

Imperforate anus was observed in four patients (10.8%) and vesicoureteral reflux was found in three patients (8.1%), with no significant difference in the frequencies of such anomalies between groups A and B. In addition, a complex urogenital malformation including penile agenesis was identified in one patient. Plasma atRA values were above the reference range in nine of 12 patients examined, and were similar between groups A and B and between patients with and without anomalies.

CONCLUSIONS

The results imply that aberrant atRA metabolism due to CYP26 deficiency underlies various anorectal and urinary anomalies in patients with PORD. Clinical phenotypes may be primarily determined by maternal oral retinol intake during pregnancy, and plasma atRA values may be largely influenced by the amount of postnatal oral retinol intake in such patients.

Overexpression of Sall1 in vivo leads to reduced body weight without affecting kidney development

Human SALL1 is a homologue of the Drosophila region-specific homeotic gene sal, and is also known as a causative gene for Townes-Brocks syndrome, which is characterized by multi-organ malformations. We previously demonstrated that mouse Sall1 plays a crucial role in ureteric bud invasion during kidney development, and possibly in nephron progenitor cells in the metanephric mesenchyme. To gain insights into the Sall1 functions in the kidney and other tissues, we generated R26Sall1 mice, in which Rosa26 locus stop sequences flanked by two loxP sites were located upstream of the Sall1 cDNA. This allele allowed exogenous Sall1 expression in a Cre recombinase-dependent manner. R26Sall1 mice were first crossed with CAGCre mice, which expressed Cre recombinase ubiquitously during embryogenesis. Mice expressing Sall1 ubiquitously were smaller in size compared with mice of other genotypes. We then crossed R26Sall1 mice with Six2Cre mice expressing Cre recombinase in the metanephric mesenchyme during kidney development. However, no kidney defects were observed. Taken together, overexpression of Sall1 does not affect kidney development, but does lead to a reduced body weight, suggesting that the optimal dosage of Sall1 is required for normal mouse development.

Mutations in SPINT2 cause a syndromic form of congenital sodium diarrhea

Autosomal-recessive congenital sodium diarrhea (CSD) is characterized by perinatal onset of a persistent watery diarrhea with nonproportionally high fecal sodium excretion. Defective jejunal brush-border Na(+)/H(+) exchange has been reported in three sporadic patients, but the molecular basis of the disease has not been elucidated. We reviewed data from a large cohort of CSD patients (n = 24) and distinguished CSD associated with choanal or anal atresia, hypertelorism, and corneal erosions--i.e., a syndromic form of CSD--occurring in ten families from an isolated form--i.e., classic CSD--presenting in seven families. Patients from both groups have a high risk of mortality due to immediate electrolyte imbalances and complications from long-term parenteral nutrition in the first years of life, but survivors can eventually adapt to partial or complete enteral nutrition. A genome-wide SNP scan was applied and identified a homozygous c.593-1G-->A splicing mutation in SPINT2, encoding a Kunitz-type serine-protease inhibitor, in one extended kindred with syndromic CSD. The same mutation and four distinct, homozygous or compound heterozygous mutations (p.Y163C, c.1A-->T, c.337+2T-->C, c.553+2T-->A) were identified in all syndromic patients. No SPINT2 mutations were found in classic-CSD patients. SPINT2 mutations were associated with loss of protein synthesis or failure to inhibit the serine protease trypsin in vitro. We delineate syndromic CSD as a distinct disease entity caused by SPINT2 loss-of-function mutations. SPINT2 mutations might lead to an excess of yet unknown serine protease activity in affected tissues.

Adults with VATER association: long-term prognosis

VATER "association" is a common condition, with the diagnosis typically based on a characteristic constellation of congenital anomalies. Reported long-term follow-up information on VATER association is limited, thus making it difficult to prognosticate the future of infants and children with this condition. Further, there are few data on how often the initial diagnosis of VATER association is correct. Some information has been published on growth deficiency and mental retardation, but these data are minimal [Bull et al., 1985; Mapstone et al., 1986; Weaver et al., 1986] and for the most part look at children under the age of 10 years. We have undertaken a long-term follow-up of individuals with VATER association originally reported by Weaver et al. [1986] or diagnosed with VATER association by his associates and him after 1986. Out of the 50 patients, we were able to contact 20 individuals or families. Two of the 20 individuals had died: 1 at 3 days with cardiac failure due to a truncus arteriosus, and 1 at 4 years of unspecified cause. Two were unwilling to participate. Of the rest, we interviewed and examined seven persons, and interviewed another nine by telephone. Of the 16, 5 had some degree of cognitive impairment. These individuals were more likely to have congenital anomalies outside of the typical scope of VATER association, such as prune belly sequence or findings of CHARGE association. Of the nine individuals with a history of imperforate anus, five had partial or complete incontinence as adults leading to difficulties in maintaining employment. Height was at the 5th centile or less in 6 of 16 patients. Three of four patients who were trying to have children, had infertility. In two women, the infertility was thought to be related to congenital anomalies of the genitourinary system and multiple pelvic operations. We also present the long-term medical and neurologic problems in these individuals.

Two coding single nucleotide polymorphisms in the SALL1 gene in Townes-Brocks syndrome: a case report and review of the literature

Townes-Brocks syndrome (TBS) is an autosomal dominantly inherited malformation syndrome characterized by imperforate anus and limb and ear malformations with sensorineural hearing loss. Mutations in SALL1, a gene mapping to chromosome 16q21.1, are responsible for TBS. Here, we described a 16-month-old male patient with typical TBS clinical features including imperforate anus and preaxial polydactyly. Two coding polymorphism sites were identified in this case. One is silent (rs1965024, 2574 C > T), whereas the other yields a new codon encoding a different amino acid (rs4614723, 3823 G > A). The hot spot mutations in exon 2 were not suggested. Therefore, lack of SALL1 gene mutations and the presence of variable phenotypes in the sporadic cases might suggest DNA alternations in the noncoding regions of SALL1 gene and/or in other genes modulating SALL1 gene expression or functions.

A prenatally diagnosed case of sirenomelia with polydactyly and vestigial tail

We are presenting a prenatally diagnosed case with sirenomelia, vestigial tail and polydactyly. A 30-year-old woman at 16 weeks of gestation with dichorionic twins was admitted to the hospital. Prenatal ultrasound demonstrated fusion of the lower limbs in one member and normal femurs, tibias and fibulas, and normal vertebras in the second twin, suggesting the diagnosis of sirenomelia. The twins were delivered vaginally at 35 weeks after spontaneous onset of labor. The affected newborn died after 24 hours and postnatal examination revealed unseparated lower limbs with extreme retroversion, bilateral pes equinus, unilateral postaxial polydactyly, a vestigial tail on the sacral region, a large and wide penis and anal atresia. There is only one previous report of sirenomelia with vestigial tail in the literature. However, a large, wide penis and polydactyly have not been reported before in association with this anomaly.

Anorectal anomalies, diaphragmatic defect, cleft palate, lower lip pits, hypopigmentation and hypogammaglobulinemia A in Kabuki syndrome: a rare combination

We report a rare combination of anomalies in an Egyptian girl with Kabuki syndrome (KS). The 26-month-old girl had imperforate anus with rectovestibular fistula, diaphragmatic defect, congenital heart defects, cleft palate, lower lip pits, hypopigmentation, seizures, hypogammaglobulinemia A, hyperlaxity of joints and premature breast development. This unique combination of anomalies, proposes to carefully investigate cases with KS patient in an attempt to determine their real frequency and in order to improve clinical management. Further, it raises a question about factors determining the variability in phenotypic expression among cases with KS. To our knowledge, this is the first case of KS to be reported from Egypt.

Syndromes and Disorders Associated with Omphalocele (II): OEIS Complex and Pentalogy Of Cantrell

Omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is characterized by a combination of omphalocele, exstrophy of the bladder, an imperforate anus, and spinal defects. Pentalogy of Cantrell is characterized by a combination of a midline supraumbilical abdominal wall defect, a defect of the lower sternum, a defect of the diaphragmatic pericardium, a deficiency of the anterior diaphragm, and congenital cardiac anomalies. This article provides a comprehensive review of OEIS complex and pentalogy of Cantrell, including the pathogenesis, prenatal diagnosis, differential diagnosis, and associated malformations. Omphalocele is an important sonographic marker for OEIS complex and pentalogy of Cantrell. Prenatal detection of an abdominal wall defect associated with multiple midline defects should alert one to the possibility of OEIS complex and pentalogy of Cantrell and prompt the genetic investigation and counseling of the disorders.

SALL1 mutations in sporadic Townes-Brocks syndrome are of predominantly paternal origin without obvious paternal age effect

Autosomal dominant Townes-Brocks syndrome (TBS) is characterized by imperforate anus, triphalangeal and supernumerary thumbs, dysplastic ears and sensorineural hearing loss, and may also involve other organ systems. Strong inter- and intrafamiliar variability is known. Approximately 50% of TBS cases are sporadic and due to de novo mutations in the SALL1 gene. SALL1 encodes a zinc finger protein operating as a transcriptional repressor and localizing to pericentromeric heterochromatin. We traced the parental origin of SALL1 mutations in sporadic TBS by analysis of linkage between SALL1 mutations and exonic or intronic polymorphisms in 16 families with 10 different mutations. Mutations were of paternal origin in 14 of 16 cases (87.5%). Paternal origin was independent of the mutation type. The mean paternal age at conception was 29.9 and the mean maternal age 26.5 years. We conclude that de novo mutations in SALL1 mostly occur on the paternally derived chromosome 16 without an obvious age effect.

Brachyury is required for elongation and vasculogenesis in the murine allantois

Mouse conceptuses homozygous for mutations in brachyury (T) exhibit a short, misshapen allantois that fails to fuse with the chorion. Ultimately, mutant embryos die during mid-gestation. In the 60 years since this discovery, the role of T in allantoic development has remained obscure. T protein was recently identified in several new sites during mouse gastrulation, including the core of the allantois, where its function is not known. Here, using molecular, genetic and classical techniques of embryology, we have investigated the role of T in allantoic development. Conceptuses homozygous for the T(Curtailed) (T(C)) mutation (T(C)/T(C)) exhibited allantoic dysmorphogenesis shortly after the allantoic bud formed. Diminution in allantoic cell number and proliferation was followed by cell death within the core. Fetal liver kinase (Flk1)-positive angioblasts were significantly decreased in T(C)/T(C) allantoises and did not coalesce into endothelial tubules, possibly as a result of the absence of platelet endothelial cell adhesion molecule 1 (Pecam1), whose spatiotemporal relationship to Flk1 suggested a role in patterning the umbilical vasculature. Remarkably, microsurgical perturbation of the wild-type allantoic core phenocopied the T(C)/T(C) vascularization defect, providing further support that an intact core is essential for vascularization. Last, abnormalities were observed in the T(C)/T(C) heart and yolk sac, recently reported sites of T localization. Our findings reveal that T is required to maintain the allantoic core, which is essential for allantoic elongation and vascular patterning. In addition, morphological defects in other extraembryonic and embryonic vascular organs suggest a global role for T in vascularization of the conceptus.

Handless, footless fetus

We report a fetus with symmetrical terminal transverse limb deficiency. Two earlier reports described patients with similar defects. These patients resemble the animal models that result from the removal of apical ectodermal ridge.

A locus for sacral/anorectal malformations maps to 6q25.3 in a 0.3 Mb interval region

Partial absence of the sacrum is a rare congenital defect that also occurs as an autosomal-dominant trait, whereas imperforate/ectopic anus is a relatively common malformation, usually observed in multiple congenital anomalies syndromes. We report on a girl born to healthy consanguineous parents (first cousins once removed) with anal imperforation and associated rectovaginal fistula and partial sacral agenesis. Facial dysmorphism included a high forehead, epicanthic folds, downslanting palpebral fissures, hypertelorism and a depressed nasal root. Brain MRI showed a bilateral opercular dysplasia with a unilateral (right) pachygyria; MRI and X-ray imaging of the spine disclosed a tethered cord associated with partial sacral agenesis. She showed a moderate developmental delay. Ophthalmologic examination evidenced bilateral microphthalmos and relative microcornea. Cytogenetic studies in our patient disclosed a pure de novo 6q25.3 --> qter deletion. By genotype analysis, we detected in our patient a maternal allele loss encompassing D6S363 and D6S446. Pure distal 6q deletion is a rare anomaly, reported in association with sacral/anorectal malformations (sacral agenesis, anal imperforation/ectopia) and never with cortical dysplasia. Pooling deletion mapping information in patients with pure terminal and interstitial 6q deletion allowed us to define a critical region spanning 0.3 Mb between the markers D6S959 and D6S437 for sacral/anal malformations. We hypothesize that haploinsufficiency for a gene within the deleted region may impair normal development of caudal structures, possibly acting on the notochordal development. European Journal of Human Genetics (2006) 14, 971-974. doi:10.1038/sj.ejhg.5201635; published online 17 May 2006.

Symptomatic anal anomalies in chromosome 22q11 deletion syndrome: a report of three patients

Deletion of chromosome 22q11 is a common genetic condition with varying clinical presentation ranging from neonatal fatality to patients whose presentation to medical services will be prompted after a few years by speech delay or mild developmental concerns. While most published data relating to patients with 22q11 deletions has focused on the "classical" presentation of the condition with cardiac manifestations, hypocalcaemia and velopharyngeal insufficiency, a much wider range of clinical presentations can characterise this syndrome. Anal anomalies, comprising imperforate anus and symptomatic anal stenosis, are a rarely described presentation of this multisystem disorder. In this report we document three patients presenting to paediatric services with symptoms attributed initially to symptomatic anal stenosis/atresia.

Shprintzen–Goldberg omphalocele syndrome: A new patient with an expanded phenotype

Shprintzen and Goldberg [1979] described a new autosomal dominant syndrome characterized by omphalocele, scoliosis, pharyngeal and laryngeal hypoplasia, mild dysmorphic face, and learning disabilities. This condition was described in a father and three daughters, one of whom died in infancy, probably of airway narrowing. Here, we report on a second observation of this syndrome in a 6-year-old patient. In our case, omphalocele, imperforate anus, and feeding impairment were the main clinical problems in the neonatal period. Scoliosis appeared during the fourth year of age. The facial appearance is similar to the original patients and additional clinical findings are described which expand the phenotypic spectrum.

Cat-eye syndrome with isolated idiopathic hypogonadotropic hypogonadism

A 34-year-old Japanese man diagnosed as having cat-eye syndrome (CES) with isolated idiopathic hypogonadotropic hypogonadism (IHH) was treated at our university. He showed preauricular pits/tags, downward slanting palpebral fissures, ocular hypertelorism, and strabismus. However, ocular coloboma and anal atresia, major characteristic features of CES, were negative. Chromosomal analysis revealed malformation in chromosome 22 and eunuchoid features and a low grade development of secondary sexual characteristics were also evident. Endocrinological examinations revealed that this patient was in a state of isolated IHH. Although CES with IHH is extremely rare, endocrine disorders should be given due attention.

Atresia Ani in the Dog: A Retrospective Study

Congenital anomalies of the rectum and anus are rare in dogs. The most frequently reported anomaly is atresia ani. Four types of atresia ani have been reported, including congenital anal stenosis (Type I); imperforate anus alone (Type II) or combined with more cranial termination of the rectum as a blind pouch (Type III); and discontinuity of the proximal rectum with normal anal and terminal rectal development (Type IV). An increased incidence was found in females and in several breeds, including miniature or toy poodles and Boston terriers. Surgical repair is the treatment of choice, but postoperative complications can occur, including fecal incontinence and colonic atony secondary to prolonged preoperative distension.

Successful surgical correction of anal atresia in a transgenic cloned piglet

Inbred strains of pig become indispensable for a wide range of biological studies. In biomedical science, it is generally accepted that somatic cell nuclear transfer (SCNT) technology with inbreed strain of pig is essential for xenotransplantation. In this study, we observed the anal atresia in a cloned pig which was derived from fetal fibroblast of inbreed miniature pig. A presumptive anal site of the cloned pig was excised and the rectum was sutured to apposed skin for treatment. This cloned piglet seemed to be normal with healthy status after surgery. This report can be useful for the treatment of anal atresia of cloned piglets.

Genomewide scan for anal atresia in swine identifies linkage and association with a chromosome region on Sus scrofa chromosome 1

Anal atresia is a rare and severe disorder in swine occurring with an incidence of 0.1-1.0%. A whole-genome scan based on affected half-sibs was performed to identify susceptibility loci for anal atresia. The analysis included 27 families with a total of 95 animals and 65 affected piglets among them. Animals were genotyped for 126 microsatellite markers distributed across the 18 autosomal porcine chromosomes and the X chromosome, covering an estimated 2080 cM. Single-point and multipoint nonparametric linkage scores were calculated using the computer package ALLEGRO 1.0. Significant linkage results were obtained for chromosomes 1, 3, and 12. Markers on these chromosomes and additionally on chromosomes for which candidate genes have been postulated in previous studies were subjected to the transmission disequilibrium test (TDT). The test statistic exceeded the genomewide significance level for adjacent markers SW1621 (P = 7 x 10(-7)) and SW1902 (P = 3 x 10(-3)) on chromosome 1, supporting the results of the linkage analysis. A specific haplotype associated with anal atresia that could prove useful for selection against the disorder was revealed. Suggestive linkage and association were also found for markers S0081 on chromosome 9 and SW957 on chromosome 12.

Characterization of a new syndrome that associates craniosynostosis, delayed fontanel closure, parietal foramina, imperforate anus, and skin eruption: CDAGS

We describe the clinical characterization, molecular analyses, and genetic mapping of a distinct genetic condition characterized by craniosynostosis, delayed closure of the fontanel, cranial defects, clavicular hypoplasia, anal and genitourinary malformations, and skin eruption. We have identified seven patients with this phenotype in four families from different geographic regions and ethnic backgrounds. This is an autosomal recessive condition that brings together apparently opposing pathophysiologic and developmental processes, including accelerated suture closure and delayed ossification. Selected candidate genes--including RUNX2, CBFB, MSX2, ALX4, TWIST1, and RECQL4--were screened for mutations, by direct sequencing of their coding regions, and for microdeletions, by fluorescent in situ hybridization. No mutations or microdeletions were detected in any of the genes analyzed. A genomewide screen yielded the maximum estimated LOD score of +2.38 for markers D22S283 and D22S274 on chromosome 22q12-q13. We hypothesize that the gene defect in this condition causes novel context-dependent dysregulation of multiple signaling pathways, including RUNX2, during osteoblast differentiation and craniofacial morphogenesis.

Genetic analysis of anal atresia in pigs: evidence for segregation at two main loci

Anal atresia is a relatively common congenital malformation that occurs in about 1 out of 5000 infants, caused by abnormal hindgut development of the embryo, often associated with other developmental anomalies (e.g., Currarino, Townes-Brock, Pallister-Hall syndromes, and VATER association). Genetic analysis in human families is exceedingly difficult due to the multifactorial nature of the trait. In pigs, anal atresia occurs at a higher incidence (0.18%) than in humans. A complete genome scan (165 microsatellite markers) was performed using a backcross pedigree previously obtained by crossing affected animals from a partially inbred line, selected for a high incidence of anal atresia, with an unaffected male of a different breed (Meishan). The data set was analyzed with classical linkage (TWOPOINT) and nonparametric genetic methods (NPL, Non-Parametric Linkage, and TDT, Transmission Disequilibrium Test). Both methods support association of the trait with two loci on Chromosomes 9 and 15. GLI2 (GLI-Kruppel family member GLI2) was identified as a positional candidate gene based on comparative mapping; radiation hybrid mapping confirmed that this locus is located within the QTL region.

Isolated imperforate anus in monozygotic twins: case report and implications

The authors report a case of isolated imperforate anus with perineal fistula in monozygotic twins. Only 4 other well-documented cases of monozygotic twins concordant for isolated anorectal malformation have been reported in the literature. In all these cases the defect occurred below the levator ani muscle. This case confirms previous reports on the incidence of low anorectal anomalies in monozygotic twins where the defect was isolated. A review of the literature relating to this condition in twins and siblings points toward low anomalies and more severe malformations having different genetic backgrounds.

Deletion involving the TWIST locus and the HOXA cluster: a contiguous gene syndrome on 7p?

Deletion of TWIST on 7p21 leads to Saethre-Chotzen syndrome, whereas deletion of the HOXA cluster on 7p15.2 leads to hand-foot-genital syndrome. We report here a patient with 46,XY,del(7)(p15.2p21) who had craniosynostosis, maxillary hypoplasia, prominent ear crus, rectoperineal fistula, and hypoplastic fifth fingers. Using fluorescence in situ hybridization, we demonstrated the deletion to encompass the TWIST locus and the HOXA cluster. We suggest that many, if not all, of the features of this patient could be accounted for by combined haploinsufficiency of the TWIST and HOXA cluster. Hence, the patient's phenotype may define a new contiguous gene syndrome on 7p.

Primary immunodeficiency in combination with transverse upper limb defect and anal atresia in a 34-year-old patient with Jacobsen syndrome

We describe a 34-year-old male patient with Jacobsen syndrome associated with a broad spectrum of anomalies and an increased susceptibility to infections. Features commonly seen in Jacobsen syndrome were short stature, mental retardation, congenital heart disease, cryptorchidism, strabismus, distal hypospadia glandis, and mild thrombocytopenia. Chromosome analysis disclosed a mosaic 46,XY,del(11)(q24.1)/46,XY karyotype with a very low percentage of normal cells. In addition, transverse upper limb defect, imperforate anus, and hearing impairment were noted. Cellular anomalies include functional impairment and deficiency of T-helper cells, and a low serum immunoglobulin M (IgM)-level. The presence of a transverse limb defect and primary immunodeficiency has not been reported previously in Jacobsen syndrome.

A case of acrocephalosyndactyly with low imperforate anus

The authors report a case of a female acrocephalosyndactyly with imperforate anus without fistula, which is rare in girls. Acrocephalosyndactyly is characterized by premature closure of the sutures (craniosynostosis) and fusion or webbing of hands and feet (syndactyly). The most general types of the syndrome are the Apert syndrome and the Pfeiffer syndrome. They usually have some fibroblast growth factor receptor (FGFR) gene mutations, so that acrocephalosyndactyly is thought to be involved in "FGFR-related craniosynostosis." To the authors' knowledge, only 4 cases of anorectal anomaly in acrocephalosyndactyly have been reported in the world. The relationship between anorectal anomaly and the FGFR gene is not clear now, but might be clarified in the future.

Blepharocheilodontic (BCD) syndrome: expanding the phenotype?

We describe affected individuals in three generations of a family and another sporadic case, all Brazilian patients, with a combination of signs that diagnose the BCD syndrome. In addition to the cardinal signs, the sporadic case has hypothyroidism and imperforate anus, which was observed previously in one patient. The broadened phenotype and the possibility of involvement of p63 and IRF6 genes in this condition are discussed.

VACTERL association with a cleft hand

Regarding radial ray deficiency, several reports suggest that preaxial limb anomalies occur frequently, while postaxial limb anomalies and cleft hand (split-hands) are rarely associated with VACTERL. We describe a rare clinical case of VACTERL with cleft hand and a number of visceral anomalies.

Prenatal ultrasonographic diagnosis of a recurrent case of Johanson-Blizzard syndrome

We report on ultrasonographic prenatal diagnosis of a recurrent case of Johanson-Blizzard syndrome. The pregnancy was terminated at 21 weeks'. This observation highlights the great variability of the expression of this syndrome, including in the same family, and the necessity of collaborating with an experienced geneticist in all antenatal diagnosis of any complex of abnormalities.

Hipoacusia en el síndrome de townes-brocks

In nineteen seventy two Towns and Brocks reported on a family in which the father and seven children showed anal atresia, triphalangeal thumb, metatarsal synostosis, extra fingers, neurosensorial deafness and ear abnormalities. The main traits were those related to hand, ear and anus alterations, transmitted under a dominant autosomal pattern. In this paper we present several members of the same family with similar alterations who finally were diagnosed of Townes-Brocks syndrome.