Single median maxillary central incisor: New data and mutation review

El-Jaick, Kênia Balbi; Fonseca, Renata; Moreira, Miguel Ângelo Martins; Ribeiro, Márcia Gonçalves; Bolognese, Ana Maria; Dias, Sânia O.; Pereira, Eliane T.; Castilla, Eduardo E.; Orioli, Iêda M.

doi:10.1002/bdra.20380

Cited by 34 publications

(31 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…17 The presence of SMMCI may also be a clue to HPE. [18][19][20][21] When these extracerebral anomalies are found either clinically or on imaging studies, one should perform high-resolution MR imaging. If an obvious diagnosis of classic HPE is not readily evident, careful attention should be directed to the preoptic area and septal region to look for the milder forms of HPE.…”

Section: Neuroimaging Features Comparing Lobar Versus Septopreoptic Hpementioning

confidence: 99%

Septopreoptic Holoprosencephaly: A Mild Subtype Associated with Midline Craniofacial Anomalies

Hahn¹,

Barnes²,

Clegg³

et al. 2010

AJNR Am J Neuroradiol

View full text Add to dashboard Cite

SUMMARY: HPE is a congenital brain malformation characterized by failure of the prosencephalon to divide into 2 hemispheres. We have identified 7 patients who have a mild subtype of HPE in which the midline fusion was restricted to the septal region or preoptic region of the telencephalon. This subtype, which we call septopreoptic HPE, falls in the spectrum of lobar HPE, but lacks significant frontal neocortical fusion seen in lobar HPE. Other imaging characteristics include thickened or dysplastic fornix, absent or hypoplastic anterior CC, and single unpaired ACA. The SP was fully formed in 4, partially formed in 2, and absent in 1. Mild midline craniofacial malformation, such as SMMCI and CNPAS were found in 86% and 71%, respectively. Patients outside of infancy often manifested language delay, learning disabilities, or behavioral disturbances, while motor function was relatively spared.ABBREVIATIONS: AC ϭ anterior commissure; ACA ϭ anterior cerebral artery; CC ϭ corpus callosum; CNPAS ϭ congenital nasal piriform aperture stenosis; FSPGR ϭ fast-spoiled gradient-recalled; HPE ϭ holoprosencephaly; IHF ϭ interhemispheric fissure; MPR ϭ multiplanar reconstructed; SMMCI ϭ single median maxillary central incisor; SP ϭ septum pellucidum; SPGR ϭ spoiled gradient-recalled; V3 ϭ third ventricle H PE is a complex congenital brain malformation characterized by failure of the forebrain to bifurcate into 2 hemispheres, a process normally complete by the fifth week of gestation.1 As the name "HPE" implies, these nonseparated prosencephalic structures involve parts of the telencephalon and diencephalon. HPE has traditionally been classified according to DeMyer's 3 grades of severity: alobar, semilobar, and lobar.2 In addition to these classic forms, a subtype of HPE, the middle interhemispheric variant or syntelencephaly, has been characterized. 3,4 In these types of HPE, there is significant nonseparation of the neocortex of the cerebral hemispheres. In the alobar type, the entire hemispheres are involved, and in the semilobar and lobar types, the frontal lobes are primarily involved. In the middle interhemispheric variant, there is nonseparation of the posterior frontal and anterior parietal lobes in the perirolandic region. We report a series of patients who have a very mild form of HPE, in which the nonseparation is restricted to the septal (subcallosal) and/or preoptic regions or both regions (Fig 1). Patients with this type of HPE often present initially with mild midline craniofacial malformations, including SMMCI and CNPAS. Our aim was to characterize the neuroimaging and clinical findings of a mild subtype of HPE that has less neocortical fusion than classic lobar HPE. Materials and MethodsWe searched the neuroimaging data base of the Carter Centers for Research in Holoprosencephaly and Related Malformations for patients who met the criterion for a mild subtype that we call "septopreoptic HPE." The imaging criterion for inclusion was abnormal fusion restricted to the septal (subcallosal) and preoptic telencephalic re...

show abstract

Section: Neuroimaging Features Comparing Lobar Versus Septopreoptic Hpementioning

confidence: 99%

Septopreoptic Holoprosencephaly: A Mild Subtype Associated with Midline Craniofacial Anomalies

Hahn¹,

Barnes²,

Clegg³

et al. 2010

AJNR Am J Neuroradiol

View full text Add to dashboard Cite

show abstract

“…gestational diabetes, teratogen exposure), as well as to a speculative digenic model called the “multiple hit” hypothesis [16]. Clinical findings in HPE can extend from cyclopia, at the severe extreme, to less severe conditions that include several types of recognizable microforms such as the solitary median maxillary central incisor syndrome [SMMCI; see 17–20], or even incomplete penetrance of obligate mutation carriers [2, 5, reviewed in 21]. Such extreme clinical presentations are encompassed in the term the “HPE spectrum”.…”

Section: Introductionmentioning

confidence: 99%

Utilizing prospective sequence analysis of SHH, ZIC2, SIX3 and TGIF in holoprosencephaly probands to describe the parameters limiting the observed frequency of mutant gene × gene interactions

Roessler¹,

Vélez²,

Zhou³

et al. 2012

Molecular Genetics and Metabolism

View full text Add to dashboard Cite

Clinical molecular diagnostic centers routinely screen SHH, ZIC2, SIX3 and TGIF for mutations that can help to explain holoprosencephaly and related brain malformations. Here we report a prospective Sanger sequence analysis of 189 unrelated probands referred to our diagnostic lab for genetic testing. We identified 28 novel unique mutations in this group (15%) and no instances of deleterious mutations in two genes in the same subject. Our result extends that of other diagnostic centers and suggests that among the aggregate 475 prospectively sequenced holoprosencephaly probands there is negligible evidence for direct gene-gene interactions among these tested genes. We model the predictions of the observed mutation frequency in the context of the hypothesis that gene x gene interactions are a prerequisite for forebrain malformations, i.e. the “multiple-hit” hypothesis. We conclude that such a direct interaction would be expected to be rare and that more subtle genetic and environmental interactions are a better explanation for the clinically observed inter- and intra-familial variability.

show abstract

“…HPE includes a spectrum of malformations of the brain and face that involve cyclopia, midline cleft lip and palate, congenital heart disease, seizures, and mental retardation. Those affected by SMMCI with normal intelligence and normal brain imaging often have offspring with an increased incidence of a more severe manifestation of HPE [7], [12]. Other associated findings with SMMCI include hypothalamo-pituitary axis (HPA) abnormalities like pituitary insufficiency and growth hormone deficiency which can be present in up to 33% of cases, resulting in short stature [4].…”

Section: Discussionmentioning

confidence: 99%

Congenital nasal pyriform aperture stenosis in association with solitary median maxillary central incisor: unique radiologic features

Yang

Orta

Renk

et al. 2016

Radiology Case Reports

View full text Add to dashboard Cite

Solitary median maxillary central incisor (SMMCI) coexists in 34%-65% of patients initially diagnosed with congenital nasal pyriform aperture stenosis. SMMCI, a genetic syndrome, warrants consideration for further screening because of its high prevalence of other diagnostic possibilities—specifically central defects, like nasal obstruction and hypothalamo-pituitary axis abnormalities. We report on a presentation of SMMCI with congenital nasal pyriform aperture stenosis which highlights the unique radiologic features and notes the relationship between these two central associated findings in the literature.

show abstract

Single median maxillary central incisor: New data and mutation review

Cited by 34 publications

References 37 publications

Septopreoptic Holoprosencephaly: A Mild Subtype Associated with Midline Craniofacial Anomalies

Septopreoptic Holoprosencephaly: A Mild Subtype Associated with Midline Craniofacial Anomalies

Utilizing prospective sequence analysis of SHH, ZIC2, SIX3 and TGIF in holoprosencephaly probands to describe the parameters limiting the observed frequency of mutant gene × gene interactions

Congenital nasal pyriform aperture stenosis in association with solitary median maxillary central incisor: unique radiologic features

Contact Info

Product

Resources

About