Adult index patient with Currarino syndrome due to a novelHLXB9 mutation, c.336dupG (p.P113fsX224), presenting with Hirschsprung's disease, cephalgia, and lumbodynia

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.

Urological outcome in patients with Currarino syndrome

INTRODUCTION

Currarino syndrome is a type of caudal regression syndrome characterized by the association of hemisacrum, anorectal malformation and presacral mass. Only few studies on small series report the incidence of urinary dysfunction in Currarino syndrome. Our aim was to evaluate the urological outcome in patients with Currarino syndrome.

PATIENTS AND METHODS

We retrospectively reviewed all Currarino syndrome patients treated in our institution. Of 20 patients, we could evaluate the urological outcome in 16. This group of patients underwent clinical, radiological and urodynamic evaluation.

RESULTS

All 16 patients had a sacral defect, fourteen of them presenting a presacral mass (87.5%), eight a tethered cord (50%), and 7 anorectal malformations (43.7%). Eight patients underwent neurosurgical treatment for neural tube defects. In 14 patients, the presacral mass was resected. One case presented detrusor overactivity, 2 recurrent urinary tract infections and 2 vesicoureteral refluxes. Both patients with lipomyeloschisis had a neuropathic bladder. All the other patients could void the bladder spontaneously. Renal function was normal in all.

CONCLUSION

Currarino syndrome is a rare congenital disorder presenting a variable phenotype. Urological outcome is good in the majority of patients.

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.

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.

Autosomal-dominant non-syndromic anal atresia: sequencing of candidate genes, array-based molecular karyotyping, and review of the literature

INTRODUCTION

Anorectal malformations (ARM) range from mild anal to severe anorectal anomalies. Approximately 50% are estimated to be non-syndromic with multiple familial cases reported that suggest underlying genetic factors. These, however, still await identification.

MATERIALS AND METHODS

We report a familial case of non-syndromic ARM with a mother and her two children being affected. Mother and daughter had mild ARM that had only been diagnosed after the index patient was born with a more severe form and ultrashort Hirschsprung's disease. To reveal the genetic cause in our family genome-wide array analysis was carried out to ascertain microaberrations characterized by loss or gain of genomic material. In addition, sequence analysis of four major Hirschsprung's disease genes (RET, EDNRB, EDN3, and GDNF) and the HLXB9 gene was performed to identify a mutation common to all three family members; however, these analyses did not reveal any causal genetic alteration. To demonstrate the frequency of familial non-syndromic cases, we performed a literature search revealing 59 families with at least two affected members. Sufficient description of ARM phenotype and affection status of relatives to surely classify them as familial non-syndromic forms was given for 22 families.

CONCLUSION

The present family suggests that mild ARM may be overlooked in patients with non-specific clinical symptoms and that the incidence of ARM may thus be higher than previously estimated. With the new possibilities of whole exome sequencing, even small families hold the possibility to identify causal defects.

Imperfuração anal associada à agenesia parcial do sacro e lipoma pré-sacral: síndrome de Currarino

OBJETIVO: Relatar o caso de uma criança com síndrome de Currarino diagnosticada após avaliação por episódios recorrentes de infecção urinária. DESCRIÇÃO DE CASO: Menina branca de dois anos, única filha de pais hígidos e sem história familiar de defeitos congênitos. A criança nasceu com imperfuração anal e com fístula retovestibular diagnosticadas no primeiro dia de vida. Por volta dos sete meses, começou a apresentar episódios recorrentes de infecção urinária, estabelecendo-se o diagnóstico de bexiga neurogênica. Na mesma ocasião, foi constatada a presença de agenesia parcial do sacro. A avaliação pela tomografia computadorizada e ressonância nuclear magnética de coluna identificou presença de fístula coincidente com a fosseta da transição lombo-sacral, observada ao exame físico; amputação da porção inferior da medula, com diminuição do número de raízes nervosas da cauda equina e massa pré-sacral de aspecto lipomatoso. Esta foi confirmada durante a cirurgia de correção do ânus imperfurado. A criança não apresentava outras dismorfias e a avaliação radiológica dos pais não identificou anormalidades sacrais. COMENTÁRIOS: A síndrome de Currarino é uma doença genética autossômica, dominante e rara caracterizada pela tríade formada por atresia anal, agenesia parcial do sacro e tumoração pré-sacral. Inclui teratomas, meningoceles, cistos entéricos e lipomas, como observado em nossa paciente. Crianças apresentando anormalidades anorretais deveriam ser sempre cuidadosamente avaliadas quanto à presença da síndrome de Currarino. A agenesia parcial do sacro é um forte indicativo da doença.

Long-term functional outcomes in children with Currarino syndrome

BACKGROUND

The aim of the study was to review the degree to which the long-term outcome and ongoing morbidity in Currarino syndrome (CS) has been established.

METHODS

Analysis of previously published reports that have included long-term outcome data in CS and review of five additional patients with CS.

RESULTS

Overall, long-term outcomes of children born with CS are not well described. Malignancy has been reported in six children of approximately 300 CS patients: four children with malignancy had a recurrence after primary excision. Malignancy has also occurred in four adults. Ongoing morbidity related to constipation, faecal incontinence, neurogenic bladder, urinary incontinence and presacral abscess, and more rarely meningitis, brain metastases, developmental delay and unusual gait. Almost certainly, previous reports have under-estimated the true incidence of these problems, given the methodology and focus of these series.

CONCLUSIONS

There is paucity of information on the long-term outcomes in CS. Few authors have focused on ongoing symptoms, such that we speculate the true incidence of long-term urinary and bowel dysfunction may have been under-estimated in CS. Greater emphasis on the functional assessment of these systems during childhood may help predict the long-term outcome in CS. The most severe cases are diagnosed during infancy and childhood, and these are also the ones who are more likely to have ongoing long-term morbidity.

MNX1 (HLXB9) mutations in Currarino patients

PURPOSE

The combination of partial absence of the sacrum, anorectal anomalies, and presacral mass constitutes Currarino syndrome (CS), which is associated with mutations in MNX1 motor neuron and pancreas homeobox 1 (previously HLXB9). Here, we report on the MNX1 mutations found in a family segregating CS and in 3 sporadic CS patients, as well as on the clinical characteristics of the affected individuals.

METHODS

MNX1 mutations were identified by direct sequencing the coding regions, intron/exon boundaries of MNX1 in 5 CS Japanese family members and 3 Chinese sporadic cases and their parents.

RESULTS

There were 2 novel (P18PfsX37, R243W) and 2 previously described (W288G and IVS2 + 1G > A) mutations. These mutations were not found in 198 control individuals and are predicted to impair the functioning of the MNX1 protein.

CONCLUSIONS

The variability of the CS phenotype among related or unrelated patients bearing the same mutation advocates for differences in the genetic background of each individual and invokes the implication of additional CS susceptibility genes.