Microcephaly, sensorineural deafness and Currarino triad with duplication-deletion of distal 7q

Prenatal detection of chromosome 7q deletion with duplication: A case report and literature review

RATIONALE

With advances in prenatal diagnostic techniques, chromosomal microdeletions and microduplications have become the focus of prenatal diagnosis. 7q partial monosomy or trisomy due to a deletion or duplication of the 7q end is relatively rare and usually originates from parents carrying a balanced translocation.

PATIENT CONCERNS

Noninvasive prenatal screening (NIPT) showed a fetus with partial deletion and duplication of chromosome 7q. It was not possible to determine whether the fetus was normal.

DIAGNOSES

Conventional chromosome G-banding and chromosome microarray analysis (CMA) were performed on fetal amniotic fluid samples and parental peripheral blood samples.

INTERVENTIONS

The pregnant women were given detailed genetic counseling by clinicians.

OUTCOMES

The fetal karyotype was 46, XY on conventional G-banding analysis. The CMA test results showed a deletion of approximately 7.8 Mb in the 7q36.1q36.3 region and a duplication of 6.6Mb in the 7q35q36.1 region. The parents' karyotype analysis and CMA results were normal, indicating a new mutation.

LESSONS

CMA molecular diagnostic analysis can effectively detect chromosomal microdeletions or microduplications, clarify the relationship between fetal genotype and clinical phenotype, and provide a reference for prenatal diagnosis of chromosomal microdeletion-duplication syndrome.

Currarino Syndrome in Two Moroccan Siblings with Inherited 7q36 Deletion due to Maternal t(7;21)(q36;p11)mat: A Case Report

Introduction

Currarino syndrome is a rare syndrome with multiple congenital anomalies including sacral agenesis, anorectal malformation, and presence of a presacral mass. Currarino syndrome is considered to be an autosomal dominant inherited disorder, with low penetrance and variable expressivity, but sporadic cases have also been reported. Mutations in MNX1 gene, mapped to 7q36, are the main causes of this syndrome. To the best of our knowledge, less than 400 cases of this syndrome have been mentioned in the literature. Currarino syndrome is often seen in children and considered to be rare in adults; it is mostly found as incidental finding and suspected to be underdiagnosed.

Case Presentation

Recognizing the rarity of this syndrome, we present here two siblings with incomplete form of Currarino syndrome combined with microcephaly and intellectual disability. Banding and molecular cytogenetics were used to characterize the origin of this disorder. Banding cytogenetics together with molecular cytogenetics revealed an unbalanced translocation t(7;21)(q36.2;p11.3)mat, leading to a deletion of the 7q36 region in both affected children.

Conclusion

This report highlights the importance of cytogenetics in diagnosis of rare genetic syndromes, with impact on genetic counseling of patients and their families. To the best of our knowledge, this is the first Moroccan Currarino syndrome case due to an unbalanced translocation leading to a der(7)t(7;21)(q36.2;p11.3). Also, this is the first Currarino syndrome case associated with a deletion in 7q36 to be reported in Morocco.

Pure Interstitial 7q21.3-q 31.1 Duplication: A Rare Segmental Genomic Aneuploidy: Case Report and Review of Cases with Distal and Similar Segment Involved

In children with developmental delay (DD) and neurologic impairment, diagnosis can be challenging because of the wide spectrum of causes. Since the last decade, the use of array comparative genomic hybridization (CGH) offered a great contribution to get a diagnosis in complex phenotypes. The chromosome 7 is subject of interest in medical genetics because of its frequent association with chromosome aberrations, rearrangements, and deletions involving clinical manifestations. We hereby reported a 3-year-old male child patient with severe neuro-DD, craniofacial dysmorphisms, and pulmonary stenosis, whose array CGH analysis disclosed a duplication of 14.4 Mb on chromosome 7 (7q21.3-7q31.1). By reviewing the current literature to date, we first reported on neurologic and dysmorphic anomalies related to this rearrangement which was not previously reported.

Congenital Spinal Cysts: An Update and Review of the Literature

Congenital spinal cysts are rare and encompass a wide variety of diseases including arachnoid, enterogenous, teratomatous, neurenteric, foregut, bronchogenic, epithelial, ependymal, dermoid, and epidermoid cysts. Here, we elucidate the epidemiology, pathology, pathogenesis, and diagnostic findings of the most common congenital spinal cysts, followed by a discussion of their presentation and treatment options. Differentiating the cause of each lesion is crucial for targeted clinical and surgical management for the patient. Our review describes how arachnoid cysts can be observed, fenestrated, percutaneously drained, or shunted; however, the primary goal for neurenteric, dermoid, and epidermoid cysts is removal. Further, we discuss how patient presentation is dependent on the rate of growth and location of compression on the spinal cord and nerve roots. However, although many of these lesions are discovered incidentally on imaging, the spectrum of possible symptoms include pain, weakness, ataxia, bladder incontinence, and progressive or acute neurologic deficits. We present and review the histology and imaging of a variety of cysts and discuss how although the goal of treatment is resection, the risks of surgery must be considered against the benefits of complete resection in each case.

Novel MNX1 mutations and genotype-phenotype analysis of patients with Currarino syndrome

Background

Currarino syndrome (CS) is a specific complex of congenital caudal anomalies, including anorectal malformations, presacral mass and sacral anomalies. Mutations in the MNX1 gene are closely related to CS and occur in almost all familial cases and less than half of sporadic patients. We investigated the spectrum of MNX1 pathogenic variants and associated clinical features in Chinese patients with CS.

Results

Seventeen index patients from 16 families were recruited from 2015 to 2018. All patients were diagnosed with CS and treated at the Capital Institute of Pediatrics Affiliated Children’s Hospital. Genetic testing was applied to identify mutations in CS patients and their relatives by whole-exome sequencing and Sanger sequencing. Functional verification was performed for a recurrent noncanonical splice site variant in MNX1 with a minigene splicing assay. In 17 CS patients, 14 were complete CS and 3 were mild CS. Nine variants in MNX1 were identified in 11 patients, and these included two frameshift mutations (p.Leu223Leufs*61, p.X402Serfs*70), four nonsense mutations (p.Gly42X, p.Cys88X, p.Gln24X, p.Cys241X), one missense mutation (p.Trp288Leu), one splice region variant (c.691 + 3G > T) and one polyalanine polymorphism (p.Ala135insAlaAla). Seven of these nine variants have never been reported. Pathogenic MNX1 mutations were found in 100% (4/4) of familial and 46% (6/13) of sporadic patients.

Conclusion

Our study expanded the mutation spectrum of MNX1 and provided clinical and genetic analyses of seventeen CS patients from mainland China.

4q27 deletion and 7q36.1 microduplication in a patient with multiple malformations and hearing loss: a case report

BACKGROUND

Chromosome deletions of the long arm of chromosome 4 in 4q syndrome are characterized by mild facial and digital dysmorphism, developmental delay, growth retardation, and skeletal and cardiac anomalies, which is regarded as an autism spectrum disorder. Moreover, some scarce reports indicate that patients with 4q interstitial deletion and 7p duplication may present symptoms associated with hearing loss.

CASE PRESENTATION

A boy with a severe developmental delay not only post-natal but also intrauterine and several dysmorphic features including microcephaly, ocular hypertelorism, exophthalmos, low-set ears, single palmar flexion crease, and overlapping toes presented discontinued cyanosis and recurrent respiratory infections. MRI, BAEP, echocardiogram and bronchoscopy revealed that he had persistent falcine sinus with a thin corpus callosum, left auditory pathway disorder, patent foramen ovale (2 mm), and tracheobronchomalacia with the right superior bronchus arising from the lateral posterior wall of the right main bronchus. Finally, the patient died with severe pneumonia at 10 months. Array CGH revealed a 23.62 Mb deletion at chromosome 4q27, arr [hg19] 4q27-q31.21 (121, 148, 089-144, 769, 263) × 1, and a 0.85 Mb duplication at chromosome 7q36.1, arr [hg19] 7q36.1-q36.2 (152, 510, 685-153, 363,5 98) × 3. It is rare for 4q syndrome cases or 7q duplications previously reported to have a hearing disorder, pulmonary dysplasia, and pulmonary arterial hypertension.

CONCLUSIONS

The phenotype of our patient mainly reflects the effects of haploinsufficiency of FGF2, SPATA5, NAA15, SMAD1, HHIP genes combined with a microduplication of 7q36.1.

7q31.32 partial duplication: First report of a child with dysmorphism, autistic spectrum disorder, moderate intellectual disability and, epilepsy. Literature review

INTRODUCTION

Duplication of long arm of chromosome 7(q) is uncommon. It may occur as "pure", isolated anomaly or in association with other mutations involving the same or other chromosomes. "Pure" chromosome 7q duplication has recently been classified by segment involved: the interstitial, proximal, or distal segment of the arm. Attempts to correlate genotype with phenotype in each group has yielded questionable results even though intellective disability and minor dysmorphic features of variable types are typically seen.

MATERIAL AND METHODS

In a young boy showing minor facial dysmorphism, language delay, autistic spectrum disorder, epileptic seizures, behavioral disturbances and irritability an array-CGH analysis was carried out.

RESULTS

Array-CGH analysis found in the proband a de novo variant of partial duplication of 7q31.32 (122.254.792-122.376.908).

DISCUSSION

A very few cases of partial 7q duplication have been reported thus far mainly presenting with clinical signs of dysmorphic features, large head, developmental delay, epileptic seizures and skeletal anomalies. To our knowledge, this is the first report of a case of a de novo variant of 7q31.32 duplication, showing dysmorphic anomalies and neurologic impairment including ASD and seizures. In the 7q31.32 region is located the gene CADPS2, which has been associated to autistic spectrum disorder and other neurologic disorders. In the child, a genotype-phenotype correlation may be hypothesized. Further similar reports may be useful to confirm this observation.

Elongated conus medullaris, sacral agenesis and scoliosis- a case report of a patient with trisomy 19q and monosomy 7q

BACKGROUND

Both progression of scoliosis following completion of growth, and the combination of low mental retardationand the conspicuous sagittal clinical and radiographic abnormalities suggest a secondary genesis of the scoliosis according to a genetic aberration.

CASE DISCRIPTION

In the outpatient department, an 18-year-old girl presents with scoliosis and mild mental retardation. Radiography findings demonstrate a sacral agenesis and the consecutively performed MRI a conus depression. Due to the symptom constellation, a genetic syndrome was suspected. Genetic diagnostics revealed a trisomy 19q and monosomy 7q. Usually, deletions of the subtelomer 7q show a phenotype with growth retardation, facial anomalies and intellectual deficit, trisomy of the subtelomer 19q growth retardation, atypical ears, short neck and intellectual deficit with delayed development. The further clinical radiological and neurological examination showed no evidence of a tethered cord syndrome. The correction of scoliosis was carried out under intraoperative neurophysiological monitoring without neurologic complications.

CONCLUSIONS

In the presence of dysplastic sacral changes and accompanying elongated conus medullaris in patients with scoliosis, it is always necessary to think of rare chromosome aberrations and to initiate appropriate diagnostics before surgery. The intraoperative neurophysiological monitoring is strongly recommended, due to a morphologically not fully-excludable tethered cord syndrome.

Spectrum of MNX1 Pathogenic Variants and Associated Clinical Features in Korean Patients with Currarino Syndrome

Background

The major genetic cause of Currarino syndrome (CS), a congenital malformation syndrome typically characterized by sacral agenesis, anorectal malformation, and presence of a pre-sacral mass, is known to be pathogenic variants in motor neuron and pancreas homeobox 1 (MNX1), which exist in almost all familial cases and 30% of sporadic cases. Less commonly, a large deletion or a complex rearrangement involving the 7q36 region is associated with CS. We investigated the spectrum of MNX1 pathogenic variants and associated clinical features in the Korean patients with CS.

Methods

We enrolled 25 patients with CS, including 24 sporadic cases and one familial case. Direct sequencing of MNX1 and multiplex ligation-dependent probe amplification were performed. We also analyzed clinical phenotypes and evaluated genotype-phenotype correlations.

Results

We identified six novel variants amongst a total of six null variants, one missense variant, and one large deletion. The null variants included four frameshift variants (p.Gly98Alafs^*124, p.Gly145Alafs^*77, p.Gly151Leufs^*67, and p.Ala216Profs^*5) and two nonsense variants (p.Tyr186^* and p.Gln212^*). The missense variant, p.Lys295Gln, was located in the highly-conserved homeobox domain and was predicted to be deleterious. A large deletion involving the 7q36 region was detected in one patient. Pathogenic variants in MNX1 were detected in 28% of all CS cases and 25% of sporadic cases. The clinical phenotype was variable in patients with and without pathogenic variants; no significant genotype-phenotype correlation was observed.

Conclusions

This study revealed the spectrum and phenotypic variability of MNX1 pathogenic variants in the Korean population.

Medulloblastoma in association with sacral agenesis; a case report

Medulloblastoma is a congenital brain tumor which can be associated with different congenital anomalies. However, coincidence of cerebellar medulloblastoma with sacral agenesis has not been reported so far. A variety of genetic and/or environmental predisposing factors have been proposed for both diseases. Herein, an unprecedented coincidence of these two conditions is presented. A neonate was born with lumbosacral agenesis, paraplegia, and atrophic legs, and he developed medulloblastoma with three ventricular hydrocephalus 3 years later. Different aspects regarding the embryology and etiology of both ailments are discussed, assuming the possibility that the same genetic and/or environmental risk factors may have played a part in both conditions.

Currarino syndrome and microcephaly due to a rare 7q36.2 microdeletion: a case report

Background

Currarino syndrome is a rare condition characterized by presacral mass, anorectal malformation and sacral dysgenesis.

Case presentation

We report the case of a child that presented chronic constipation, encopresis and mycrocephaly. The characteristics were initially compatible with a case of functional constipation and a therapy with polyethylene glycol was prescribed. After a year, because of poor response, a plain abdominal X-ray was performed, detecting sacrum abnormalities. Finally, a CGH-array analysis was performed and a form of Currarino Syndrome caused by a rare 7q36 microdeletion, was diagnosed.

Conclusion

Occult spinal dysraphism should be suspected in case of poor polyethylene glycol responder constipation, even when evident sacral abnormalities on the physical examination are not detected.

Phenotype analysis impacts testing strategy in patients with Currarino syndrome

Currarino syndrome (OMIM 175450) presents with sacral, anorectal, and intraspinal anomalies and presacral meningocele or teratoma. Autosomal dominant loss-of-function mutations in the MNX1 gene cause nearly all familial and 30% of sporadic cases. Less frequently, a complex phenotype of Currarino syndrome can be caused by microdeletions of 7q containing MNX1. Here, we report one familial and three sporadic cases of Currarino syndrome. To determine the most efficient genetic testing approach for these patients, we have compared results from MNX1 sequencing, chromosomal microarray, and performed a literature search with analysis of genotype-phenotype correlation. Based on the relationship between the type of mutation (intragenic MNX1 mutations vs 7q microdeletion) and the presence of intellectual disability, growth retardation, facial dysmorphism, and associated malformations, we propose a testing algorithm. Patients with the classic Currarino triad of malformations but normal growth, intellect, and facial appearance should have MNX1 sequencing first, and only in the event of a normal result should the clinician proceed with chromosomal microarray testing. In contrast, if growth delay and/or facial dysmorphy and/or intellectual disability are present, chromosomal microarray should be the first method of choice for genetic testing.

Currarino syndrome: report of five consecutive patients

INTRODUCTION

The Currarino syndrome is regarded as a developmental disorder based on its recognized etiological heterogeneity. This syndrome is thought to result from abnormal separation of the neuroectoderm from the endoderm. Our aim was to report the neurosurgical management of Currarino syndrome in children and adults and to describe what clinician could do if the Currarino triad was suspected.

CASE REPORTS

We present five cases of Currarino triad who underwent surgical intervention. All patients had sacral bony deformity, anorectal malformations, and anterior sacral meningocele. A 40-year-old-male had chronic constipation. He was incidentally diagnosed with Currarino syndrome. A 19-year-old-female suffered from a slight weakness in lower extremities and urinary incontinence. Her past medical history was remarkable for anal atresia. The other three cases were children.

CONCLUSION

When an anterior sacral meningocele is encountered, Currarino syndrome should be taken into consideration. Although it is rarity, the Currarino syndrome might be one of the causes of chronic constipation. Endoscopic or endoscope-assisted surgery via a posterior sacral route can be feasible for treatment of some of the patients with anterior sacral meningocele. Anterior meningocele pouch associated with Currarino syndrome will regresses over time following transdural ligation of its neck.

Currarino syndrome at Rikshospitalet 1961-2012

BACKGROUND

Currarino syndrome is a rare hereditary condition with constipation as the main symptom. The typical patient has a combination of sacral, anorectal, intraspinal and presacral anomalies. Familial cases most often have a mutation in the MNX1 gene. The majority of Norwegian Currarino patients are treated at Rikshospitalet. This article gives an account of 50 years of experience with the condition.

MATERIAL AND METHOD

The study is based on the medical records of patients with Currarino syndrome, as well as some first-degree relatives, from the period 1961-2012. We recorded the results of mutation analysis, X-ray of the sacrum, and ultrasound, MRI and/or CT scans, as well as the treatments administered.

RESULTS

We treated 29 patients over the period in question, and in addition identified seven healthy relatives with a mutation in MNX1 and one relative with a pathognomonic sacral anomaly. There were 15 familial and 14 sporadic cases. Fourteen familial cases and one of the sporadic cases were shown to have a mutation in the MNX1 gene. Phenotypic variation was pronounced, and we saw no obvious correlation between genotype and phenotype. Twenty-six of the patients had constipation and 15 underwent a colostomy. Fourteen patients required neurosurgical and seven urogenital interventions. No patients had malignant disease.

INTERPRETATION

Patients with Currarino syndrome have a highly variable clinical presentation with constipation as the main problem. In patients with a familial syndrome, a mutation in the MNX1 gene can be expected.

A 5.8 kb deletion removing the entire MNX1 gene in a Norwegian family with Currarino syndrome

Currarino syndrome (CS) is a clinically variable disorder characterized by anorectal, sacral and presacral anomalies. It is associated with loss-of-function mutations in the motor neuron and pancreas homeobox 1 (MNX1) gene. Inheritance is autosomal dominant, expression variable and penetrance incomplete. We describe a Norwegian family with typical CS in which a heterozygous deletion removes the entire MNX1 gene but no other known genes. We also report MNX1 mutations in three other Norwegian families and confirm that the GCC12 repeat (c.373_375[12]) is a normal allelic variant. This work underscores the importance of dosage analysis of MNX1 when Sanger sequencing is negative.

Familial Currarino syndrome associated with Hirschsprung disease: two cases of a mother and daughter

Currarino syndrome with Hirschsprung disease (CS-HD) is extremely rare. We present the first family with CS-HD. Case 1: A 28-year-old woman was admitted with severe abdominal distension and dyspnea. She was diagnosed with anal stenosis, hemisacrum, anterior sacral meningocele (ASM), tethered cord (TC), and short-segment aganglionosis. She underwent the modified Duhamel operation after meningocele repair and cord detethering. A bicornuate uterus, bilateral ovarian dermoid cysts, and small rectal duplication were also noted intraoperatively. Case 2: The daughter of case 1 was admitted for abdominal distension and anal stenosis at the age of 17 days. Studies revealed a hemisacrum, ASM, TC, presacral mass, atrial septal defect, polyp in the right nasal cavity, right vesicoureteral reflux, and short-segment aganglionosis. She underwent the modified Soave operation at the age of 1 year and 4 months after meningocele repair, cord detethering, and resection of the presacral mass (epidermoid cyst). In both cases, the aganglionic segments were confirmed by preoperative rectal suction biopsy and postoperative pathological examination on full-thickness rectal specimens. Some causal genes for Currarino syndrome (CS) and Hirschsprung disease (HD) are currently investigated. Thus far, 10 CS-HD cases have been reported, including 6 cases of familial CS. However, all the patients had sporadic HD. Recent reports suggest that anomalies of the enteric nerve system contribute to postoperative constipation in CS cases.

Effects of deletion and duplication in a patient with a 46,XX,der(7)t(7;17)(q36;p13)mat karyotype

Exact breakpoint determination by DNA-array has dramatically improved the analysis of genotype-phenotype correlations in chromosome aberrations. It allows a more exact definition of the most relevant genes and particularly their isolated or combined impact on the phenotype in an unbalanced state. Here, we report on a 21-year-old female with severe growth retardation, severe intellectual disability, hypoplasia of the corpus callosum, unilateral sacral hypoplasia, tethered cord, various minor facial dysmorphisms, and a telomeric deletion of about 4.4 Mb in 7q36.2->qter combined with a telomeric duplication of about 8 Mb in 17pter->p13.1. Fine mapping was achieved with the Illumina® Infinium HumanOmni1-Quad v1.0 BeadChip. Most of the major clinical features correspond to the well-known effects of haploinsufficiency of the MNX1 and SHH genes. In addition, review of the literature suggests an association of the 17p duplication with specific facial dysmorphic features and skeletal anomalies, but also an aggravating effect of the duplication-deletion for severe growth retardation as well as sacral and corpus callosum hypoplasia by one or more genes located on the proximal half of the segmental 17p duplication could be elaborated by comparison with other patients from the literature carrying either the deletion or the duplication found in our patient.

Currarino's triad diagnosed in an adult woman

PURPOSE

To report on a female patient diagnosed with Currarino's triad in adulthood.

CASE REPORT

This case presents an adult patient with a medical history of a congenital anal atresia, a partial sacral agenesis, and a surgically treated ectopic anus. After a coincidentally observed presacral mass by MRI, due to unexplained constipation later in adulthood, Currarino's triad was suspected in this patient. This triad consists of anorectal malformation(s), sacrococcygeal defects and a presacral mass of various origin. Further investigation confirmed the mass to be a meningocele, and showed a tethered cord and a syrinx.

CONCLUSIONS

In (young) patients with anorectal malformations, although having no other symptoms, further examination might be required to exclude Currarino's triad. Importance of early diagnosis and multidisciplinary assessment is recommended to establish adequate treatment if needed.