A collection of disease information resources and questions answered by our Genetic and Rare Diseases Information Specialists for Microtia-Anotia. In this paper, the term “microtia” includes anotia as the most severe end .. Several cases reports of mosaicism 46,X,der(Y)t(Y;1)(q12;q21)/ Microtia-anotia is a spectrum of congenital anomalies of the auricle ranging from mild [PubMed]; Okajima H, Takeichi Y, Umeda K, et al.

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Exome sequencing can identify coding variants specific to each individual studied and some functional annotation can usually be ascribed to the findings. High altitude and microtia in Ecuadorian patients. Other Six mutants have microtiz been reported to have ear abnormalities. In this regard, the transcription factor Goosecoid Gsca downstream target of endothelin signaling, is expressed in the pharyngeal mesenchyme around the first pharyngeal cleft and has been implicated in outer and middle ear development through mutational analyses in patients see below.

Microtia & Atresia

Case report of micfotia novel SALL1 deletion and review of the literature. When dealing with mutations of only one gene, there is familial aggregation and different forms of Mendelian inheritance are observed, autosomal recessive, autosomal dominant and X-linked.

Child health and living at high altitude.

For example, studies with Frem2 deficient mice have shown frequent hematomas, yet Frem2 itself is not expressed in the embryonic vasculature [ Timmer et al. B Type I with preauricular appendices arrow. In Treacher Collins syndrome, TCOF1 mutations result in haploinsufficiency of the protein Treacle encoded by TCOF1 leading to insufficient ribosome genesis, diminished cell proliferation, and increased neuroepithelial apoptosis.

Anotia Peanut ears are included in this group. In patients with microtia, in addition to the main genes and their regulators, syndromic cases are commonly associated with changes in the copy number such as duplications or deletions, which is found in virtually every human microtiw Table 2 suggesting that the basic defect is in a pathway of organogenesis.


The uterine artery undergoes remodeling during pregnancy to accommodate the rise in maternal uterine artery blood flow and facilitates delivery of oxygen and nutrients to the yy circulation. Transcription factor SIX5 is mutated in patients with branchio-oto-renal syndrome.

Alcohol has been inconsistently reported as a anltia factor [ Carey et al. The structures of the internal ear arise from the superficial ectoderm. Author information Copyright and License information Disclaimer. Tissue-specific roles of Tbx1 in the development of the outer, middle mkcrotia inner ear, defective in 22q11DS patients.

Maternal exposure to misoprostol has been reported for individuals presenting mainly with transverse-limb defects, Moebius sequence and arthrogryposis [ aanotia Silva Dal Pizzol et al. Ipsilateral microtia in monozygotic twins: In another study, the methylation status of the EYA1 gene promoter was analyzed in 64 individuals with microtia and 36 healthy controls. More recently, periconceptional intake of folic-acid-containing supplements has been associated with reduced risk of microtia among non-obese women [ Ma et al.

The most common anomalies associated with microtia include: Furthermore, anthropological, archaeological, linguistic, and molecular data have demonstrated that the peopling of the American continent took place by migrations originating in northeast Asia and entering America via Beringia, giving rise to Alaskan Natives and Amerindians among other populations in the Americas Jobling et al.

Chromosomal alterations and CNV associated with microtia. An important observation is that miRNA are also subject to the CNV, microtiia complexity to the underlying genome related to the appearance of microtia.

Anotia/Microtia – Diseases and Conditions Identified in Children

Congenit Anom Kyoto ; 45 4: Walter de Gruyter; Berlin: Am J Med Genet A. For example, compared to recent studies of microtia-anotia Canfield et al.

Microtia-atresia must be considered as a major malformation with important repercussions in hearing function requiring multidisciplinary medical care in order to limit the disability associated and to provide genetic counseling.


Thymus, kidney and craniofacial abnormalities in Six 1 deficient mice. In the uterine environment, the external surface of the developing embryo is constantly in contact with the uterine wall. Microtia has been part of the clinical picture in the most common aneuploidies such as trisomy 13 and A summary of the risk factors reported in the literature, in case-control and cross-sectional studies, is presented in Table III. It can occur as an isolated defect or can be associated with other abnormalities such as stenosis of the external auditory canal.

Microtia encompasses a spectrum of congenital anomalies of the auricle that range in severity from mild structural abnormalities to complete absence of the ear anotia [ Carey et al.

Other familial cases with syndromic microtia have also been reported.

Table V Summary of genes associated with microtia in mice and comparison with ear phenotypes in humans. Between and mivrotia were at least 19 familial cases identified. Among the genes associated with this syndrome, the GSC gene has been studied and no mutations have been found.

In addition, such studies will likely open new strategies for treatment for individuals with microtia. In summary, information about the association of microtia with mutations or alterations in the mivrotia of major and minor genes and their regulators such as miRNA reveals that there are a large number of loci required in the normal formation of the outer ear.

Microtia: Epidemiology & Genetics

Risks of selected congenital malformations among offspring of mixed race-ethnicity. In the cranial region, reciprocal signaling between neural crest cells ectomesenchyme and other embryonic cell types e. Hypoplasia of the superior third of the auricle.