Manitoba Oculotrichoanal (MOTA) syndrome: report of eight new cases

Ventral body wall closure: Mechanistic insights from mouse models and translation to human pathology

The ventral body wall (VBW) that encloses the thoracic and abdominal cavities arises by extensive cell movements and morphogenetic changes during embryonic development. These morphogenetic processes include embryonic folding generating the primary body wall; the initial ventral cover of the embryo, followed by directed mesodermal cell migrations, contributing to the secondary body wall. Clinical anomalies in VBW development affect approximately 1 in 3000 live births. However, the cell interactions and critical cellular behaviors that control VBW development remain little understood. Here, we describe the embryonic origins of the VBW, the cellular and morphogenetic processes, and key genes, that are essential for VBW development. We also provide a clinical overview of VBW anomalies, together with environmental and genetic influences, and discuss the insight gained from over 70 mouse models that exhibit VBW defects, and their relevance, with respect to human pathology. In doing so we propose a phenotypic framework for researchers in the field which takes into account the clinical picture. We also highlight cases where there is a current paucity of mouse models for particular clinical defects and key gaps in knowledge about embryonic VBW development that need to be addressed to further understand mechanisms of human VBW pathologies.

Bilateral cryptophthalmos with overlapping features of Manitoba oculo-tricho-anal (MOTA) syndrome and Fraser syndrome 2

A male baby with bilateral cryptophthalmos without eyebrows, distorted anterior hairline, bifid nasal tip, low-set ears, hypertelorism and low anorectal anomaly who was phenotypically diagnosed with Manitoba oculo-tricho-anal syndrome (mutation in FREM1 gene) had an overlapping genotypic diagnosis of autosomal recessive Fraser syndrome 2 because of the presence of a closely related mutation in FREM2 This heterozygous variant was likely to be sporadic. Another mutation was identified in the CEP85L gene indicating lissencephaly 10. This genetic condition has abnormal gyri pattern in the occiput area. This form of lissencephaly is characterised by phenotypic heterogeneity whereby some patients have only mild mental retardation, while others have a very complex clinical picture.In conclusion, this rare condition with the overlap of genetics between several conditions highlights the need for genetic testing even in an low middle income country (LMIC).

Facial cleft? The first case of manitoba-oculo-tricho-anal syndrome with novel mutations in China: a case report

Background

Manitoba-oculo-tricho-anal (MOTA) syndrome is a rare syndrome with only 27 cases reported worldwide so far, but none was reported in the population of Eastern Asia. Such extremely low prevalence might be contributed by misdiagnosis due to its similarities in ocular manifestations with facial cleft. In our study, we discovered the first case of MOTA syndrome in the population of China, with 2 novel FRAS1 related extracellular matrix 1 (FREM1) gene stop-gain mutations confirmed by whole exome sequencing.

Case presentation

A 12-year-old Chinese girl presented with facial cleft-like deformities including aberrant hairline, blepharon-coloboma and broad bifid nose since birth. Whole exome sequencing resulted in the identification of 2 novel stop-gain mutations in the FREM1 gene. Diagnosis of MOTA syndrome was then established.

Conclusions

We discovered the first sporadic case of MOTA syndrome according to clinical manifestations and genetic etiology in the Chinese population. We have identified 2 novel stop-gain mutations in FREM1 gene which further expands the spectrum of mutational seen in the MOTA syndrome. Further research should be conducted for better understanding of its mechanism, establishment of an accurate diagnosis, and eventually the exploitation of a more effective and comprehensive therapeutic intervention for MOTA syndrome.

A Comprehensive Assessment of Co-occurring Birth Defects among Infants with Non-Syndromic Anophthalmia or Microphthalmia

PURPOSE

Infants with anophthalmia or microphthalmia frequently have co-occurring birth defects. Nonetheless, there have been few investigations of birth defect patterns among these children. Such studies may identify novel multiple malformation syndromes, which could inform future research into the developmental processes that lead to anophthalmia/microphthalmia and assist physicians in determining whether further testing is appropriate.

METHODS

This study includes cases with anophthalmia/microphthalmia identified by the Texas Birth Defects Registry from 1999 to 2014 without clinical or chromosomal diagnoses of recognized syndromes. We calculated adjusted observed-to-expected ratios for two - through five-way birth defect combinations involving anophthalmia/microphthalmia to estimate whether these combinations co-occur more often than would be expected if they were independent. We report combinations observed in ≥5 cases.

RESULTS

We identified 653 eligible cases with anophthalmia/microphthalmia (514 [79%] with co-occurring birth defects), and 111 birth defect combinations, of which 44 were two-way combinations, 61 were three-way combinations, six were four-way combinations and none were five-way combinations. Combinations with the largest observed-to-expected ratios were those involving central nervous system (CNS) defects, head/neck defects, and orofacial clefts. We also observed multiple combinations involving cardiovascular and musculoskeletal defects.

CONCLUSION

Consistent with previous reports, we observed that a large proportion of children diagnosed with anophthalmia/microphthalmia have co-occurring birth defects. While some of these defects may be part of a sequence involving anophthalmia/microphthalmia (e.g., CNS defects), other combinations could point to as yet undescribed susceptibility patterns (e.g., musculoskeletal defects). Data from population-based birth defect registries may be useful for accelerating the discovery of previously uncharacterized malformation syndromes.

Toll-like Interleukin 1 Receptor Regulator Is an Important Modulator of Inflammation Responsive Genes

TILRR (Toll-like interleukin-1 receptor regulator), a transcript variant of FREM1, is a novel regulatory component, which stimulates innate immune responses through binding to IL-1R1 (Interleukin-1 receptor, type 1) and TLR (Toll-like receptor) complex. However, it is not known whether TILRR expression influences other genes in the NFκB signal transduction and pro-inflammatory responses. Our previous study identified FREM1 as a novel candidate gene in HIV-1 resistance/susceptibility in the Pumwani Sex worker cohort. In this study, we investigated the effect of TILRR overexpression on expression of genes in the NFκB signaling pathway in vitro. The effect of TILRR on mRNA expression of 84 genes related to NFκB signal transduction pathway was investigated by qRT-PCR. Overexpression of TILRR on pro-inflammatory cytokine/chemokine(s) secretion in cell culture supernatants was analyzed using Bioplex multiplex bead assay. We found that TILRR overexpression significantly influenced expression of many genes in HeLa and VK2/E6E7 cells. Several cytokine/chemokine(s), including IL-6, IL-8 (CXCL8), IP-10, MCP-1, MIP-1β, and RANTES (CCL5) were significantly increased in the cell culture supernatants following TILRR overexpression. Although how TILRR influences the expression of these genes needs to be further studied, we are the first to show the influence of TILRR on many genes in the NFκB inflammatory pathways. The NFκB inflammatory response pathways are extremely important in microbial infection and pathogenesis, including HIV-1 transmission. Further study of the role of TILRR may identify the novel intervention targets and strategies against HIV infection.

Novel FREM1 mutations in a patient with MOTA syndrome: Clinical findings, mutation update and review of FREM1-related disorders literature

Manitoba-oculo-tricho-anal (MOTA) syndrome is an uncommon condition arising from biallelic mutations of FREM1 gene and clinically characterized by a variable spectrum of eyelid malformations, aberrant hairline, bifid or broad nasal tip, and gastrointestinal anomalies. In this report, we describe a patient with a phenotype compatible with MOTA syndrome (aberrant anterior hair line, hypertelorism, unilateral anophthalmia, and bifid and broad nasal tip) in whom two novel FREM1 mutations (c.305 A > G, p.Asp102Gly; and c.2626delG, p.Val876Tyrfs*16) were identified in the compound heterozygous state, thus broadening the mutational spectrum of the disease. We performed a literature review of the clinical and genetic features of individuals carrying FREM1 mutations.

Congenital upper eyelid coloboma: embryologic, nomenclatorial, nosologic, etiologic, pathogenetic, epidemiologic, clinical, and management perspectives

Purpose:

To review the recent literature and describe the authors’ experience with congenital upper eyelid coloboma.

Methods:

In this review, we will summarize the embryologic and etiopathogenetic bases of congenital upper eyelid coloboma, and study the published clinical reports. We will also attempt to briefly shed some light on the rarer syndromic curiosities associated with upper eyelid coloboma.

Results:

Congenital upper eyelid colobomas are one of the few nontraumatic oculoplastic emergencies that may occasionally present in the first few days of life with a corneal ulcer and may even present with impending perforation. They can present with or without corneopalpebral adhesions, may be isolated findings or a part of a larger spectrum of congenital anomalies as in the case of Fraser syndrome or Goldenhar syndrome, or could be associated with other rare curiosities that could challenge the clinician with a huge diagnostic dilemma.

Conclusions:

Existing literature dealing with congenital colobomas of the upper eyelid is fraught with nosologic problems, confusing etiologies, and overlapping clinical features. We attempted to clarify the salient clinical features, outline the management principles, and until a time in the not-so-distant future where advances in molecular genetic testing would help redefine the etiology and the diverse clinical spectrum of genetic diseases associated with upper eyelid colobomas, we propose a simplified classification scheme based on the relation of the coloboma to the cornea, the presence or absence of systemic features, and all the syndromic and nonsyndromic associations of congenital coloboma of the upper eyelid known today.

In this review, the authors will describe the pathogenesis of upper eyelid coloboma, suggest a new simplified classification system, describe the clinical picture in detail, clarify the various syndromic associations of upper eyelid coloboma, and lay out the basic surgical principles of management.

Variable expression pattern in Donnai-Barrow syndrome: Report of two novel LRP2 mutations and review of the literature

Donnai-Barrow syndrome (DBS; MIM 222448) is characterized by typical craniofacial anomalies (major hypertelorism with bulging eyes), high grade myopia, deafness and low molecular weight proteinuria. The disorder results from mutations in the low density lipoprotein receptor-related protein 2 gene LRP2 that maps to chromosome 2q31.1. LRP2 encodes megalin, a multi-ligand endocytic receptor. Herein, we describe the clinical presentation of 4 patients from 2 unrelated Saudi families. Two novel LRP2 mutations, a homozygous nonsense mutation (c.4968C>G; p.Tyr1656*) and a missense mutation (c.12062G>A; p.Cys4021Tyr), were detected in the first and second family respectively. Interestingly, intrafamilial phenotypic variability was observed in one family, while DBS features were atypical in the second family. Differential diagnosis of DBS includes several syndromes associating hypertelorism with high grade myopia, and several syndromal forms of CDH, which are briefly summarized in this study.

Ablepharon macrostomia syndrome: A distinct genetic entity clinically related to the group of FRAS-FREM complex disorders

Ablepharon macrostomia syndrome (AMS; OMIM 200110) is an extremely rare congenital malformation syndrome. It overlaps clinically with Fraser syndrome (FS; OMIM 219000), which is known to be caused by mutations in either FRAS1, FREM2, or GRIP1, encoding components of a protein complex that plays a role in epidermal-dermal interactions during morphogenetic processes. We explored the hypothesis that AMS might be either allelic to FS or caused by mutations in other genes encoding known FRAS1 interacting partners. No mutation in either of these genes was found in a cohort of 11 patients with AMS from 10 unrelated families. These findings demonstrate that AMS is genetically distinct from FS. It is proposed that it constitutes a separate entity within the group of FRAS-FREM complex disorders.

Novel frem1-related mouse phenotypes and evidence of genetic interactions with gata4 and slit3

The FRAS1-related extracellular matrix 1 (FREM1) gene encodes an extracellular matrix protein that plays a critical role in the development of multiple organ systems. In humans, recessive mutations in FREM1 cause eye defects, congenital diaphragmatic hernia, renal anomalies and anorectal malformations including anteriorly placed anus. A similar constellation of findings-microphthalmia, cryptophthalmos, congenital diaphragmatic hernia, renal agenesis and rectal prolapse-have been described in FREM1-deficient mice. In this paper, we identify a homozygous Frem1 missense mutation (c.1687A>T, p.Ile563Phe) in an N-ethyl-N-nitrosourea (ENU)-derived mouse strain, crf11, with microphthalmia, cryptophthalmos, renal agenesis and rectal prolapse. This mutation affects a highly conserved residue in FREM1's third CSPG domain. The p.Ile563Phe change is predicted to be deleterious and to cause decreased FREM1 protein stability. The crf11 allele also fails to complement the previously described eyes2 allele of Frem1 (p.Lys826*) providing further evidence that the crf11 phenotype is due to changes affecting Frem1 function. We then use mice bearing the crf11 and eyes2 alleles to identify lung lobulation defects and decreased anogenital distance in males as novel phenotypes associated with FREM1 deficiency in mice. Due to phenotypic overlaps between FREM1-deficient mice and mice that are deficient for the retinoic acid-responsive transcription factor GATA4 and the extracellular matrix protein SLIT3, we also perform experiments to look for in vivo genetic interactions between the genes that encode these proteins. These experiments reveal that Frem1 interacts genetically with Gata4 in the development of lung lobulation defects and with Slit3 in the development of renal agenesis. These results demonstrate that FREM1-deficient mice faithfully recapitulate many of the phenotypes seen in individuals with FREM1 deficiency and that variations in GATA4 and SLIT3 expression modulate some FREM1-related phenotypes in mice.

Deficiency of FRAS1-related extracellular matrix 1 (FREM1) causes congenital diaphragmatic hernia in humans and mice

Congenital diaphragmatic hernia (CDH) is a common life-threatening birth defect. Recessive mutations in the FRAS1-related extracellular matrix 1 (FREM1) gene have been shown to cause bifid nose with or without anorectal and renal anomalies (BNAR) syndrome and Manitoba oculotrichoanal (MOTA) syndrome, but have not been previously implicated in the development of CDH. We have identified a female child with an isolated left-sided posterolateral CDH covered by a membranous sac who had no features suggestive of BNAR or MOTA syndromes. This child carries a maternally-inherited ~86 kb FREM1 deletion that affects the expression of FREM1's full-length transcripts and a paternally-inherited splice site mutation that causes activation of a cryptic splice site, leading to a shift in the reading frame and premature termination of all forms of the FREM1 protein. This suggests that recessive FREM1 mutations can cause isolated CDH in humans. Further evidence for the role of FREM1 in the development of CDH comes from an N-ethyl-N-nitrosourea -derived mouse strain, eyes2, which has a homozygous truncating mutation in Frem1. Frem1(eyes2) mice have eye defects, renal agenesis and develop retrosternal diaphragmatic hernias which are covered by a membranous sac. We confirmed that Frem1 is expressed in the anterior portion of the developing diaphragm and found that Frem1(eyes2) embryos had decreased levels of cell proliferation in their developing diaphragms when compared to wild-type embryos. We conclude that FREM1 plays a critical role in the development of the diaphragm and that FREM1 deficiency can cause CDH in both humans and mice.

A wedge-shaped anterior hairline extension associated with a tessier number 10 cleft

A wedge-shaped anterior hairline extension is a very rare skin manifestation usually associated with congenital anomalies including a Tessier number 10 cleft. Other associated conditions are the Tessier number 9 cleft, the Fraser syndrome, and the Manitoba oculotrichoanal syndrome (MOTA syndrome). The Tessier number 10 cleft features include a coloboma of the middle third of the upper eyelid, and an eyebrow divided into two portions. The medial eyebrow portion may be absent and the lateral portion is angulated vertically, joining the hairline of the scalp. This creates a wedge-shaped anterior hairline extension. Herein we report on a case of a wedge-shaped anterior hairline extension associated with the Tessier number 10 cleft.

Manitoba-oculo-tricho-anal (MOTA) syndrome is caused by mutations in FREM1

BACKGROUND

Manitoba-oculo-tricho-anal (MOTA) syndrome is a rare condition defined by eyelid colobomas, cryptophthalmos and anophthalmia/microphthalmia, an aberrant hairline, a bifid or broad nasal tip, and gastrointestinal anomalies such as omphalocele and anal stenosis. Autosomal recessive inheritance had been assumed because of consanguinity in the Oji-Cre population of Manitoba and reports of affected siblings, but no locus or cytogenetic aberration had previously been described.

METHODS AND RESULTS

This study shows that MOTA syndrome is caused by mutations in FREM1, a gene previously mutated in bifid nose, renal agenesis, and anorectal malformations (BNAR) syndrome. MOTA syndrome and BNAR syndrome can therefore be considered as part of a phenotypic spectrum that is similar to, but distinct from and less severe than, Fraser syndrome. Re-examination of Frem1(bat/bat) mutant mice found new evidence that Frem1 is involved in anal and craniofacial development, with anal prolapse, eyelid colobomas, telecanthus, a shortened snout and reduced philtral height present in the mutant mice, similar to the human phenotype in MOTA syndrome.

CONCLUSIONS

The milder phenotypes associated with FREM1 deficiency in humans (MOTA syndrome and BNAR syndrome) compared to that resulting from FRAS1 and FREM2 loss of function (Fraser syndrome) are also consistent with the less severe phenotypes resulting from Frem1 loss of function in mice. Together, Fraser, BNAR and MOTA syndromes constitute a clinically overlapping group of FRAS-FREM complex diseases.

Familial upper eyelid coloboma with ipsilateral anterior hairline abnormality: two new reports of MOTA syndrome

We describe two patients with upper eyelid coloboma, hypertelorism, disruption of the eyebrow, and anterior hairline anomaly. The phenotype in our patients is consistent with Manitoba Oculotrichoanal syndrome (MOTA syndrome, OMIM 248450), which comprises a variable spectrum of eyelid malformations ranging from cryptophthalmos to upper eyelid colobomas; aberrant ipsilateral anterior hairline, and anal anomalies. It was first described in members of the indigenous population of the Island Lake region of Northern Manitoba, Canada. Autosomal recessive inheritance is demonstrated in these families and single-gene etiology has been proposed. This constellation of anomalies also corresponds to those arising from the Number 10 cleft in Tessier's anatomical classification of clefting malformations. Tessier Number 10 clefts are the rarest of the 15 craniofacial clefting malformations first described by Tessier [Tessier (1976); J Maxillofac Surg 4:69-92]. They have only ever been reported as sporadic occurrences and the underlying etiology is thought to be environmental. We believe the phenotype in our patients and in those previously described with MOTA syndrome represents a disorder of craniofacial clefting; specifically, one that occurs along the tissue planes of the Tessier Number 10 cleft. The familial clustering of these facial features and their variable association with other congenital anomalies supports a genetic rather than environmental cause. The mapping of the gene for this syndrome is likely to involve a combined functional and positional approach with a focus on candidate genes involved in craniofacial development.