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    Question pallister hall syndrome

    think of pallister hall syndrome

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    Pallister-Hall syndrome is a disorder that affects the development of many parts of the body. Most people with this condition have extra fingers and/or toes (polydactyly), and the skin between some fingers or toes may be fused (cutaneous syndactyly). An abnormal growth in the brain called a hypothalamic hamartoma is characteristic of this disorder. In many cases, these growths do not cause any medical problems; however, some hypothalamic hamartomas lead to seizures or hormone abnormalities that can be life-threatening in infancy. Other features of Pallister-Hall syndrome include a malformation of the airway called a bifid epiglottis, an obstruction of the anal opening (imperforate anus), and kidney abnormalities. Although the signs and symptoms of this disorder vary from mild to severe, only a small percentage of affected people have serious complications.


    Genetics
    Mutations in the GLI3 gene cause Pallister-Hall syndrome. The GLI3 gene provides instructions for making a protein that controls gene expression, which is a process that regulates whether genes are turned on or off in particular cells. By interacting with certain genes at specific times during development, the GLI3 protein plays a role in the normal shaping (patterning) of many organs and tissues before birth. Defects in the same gene also cause Greig cephalopolysyndactyly syndrome.

    Mutations that cause Pallister-Hall syndrome typically lead to the production of an abnormally short version of the GLI3 protein. Unlike the normal GLI3 protein, which can turn target genes on or off, the short protein can only turn off (repress) target genes. Researchers are working to determine how this change in the protein's function affects early development. It remains uncertain how GLI3 mutations can cause polydactyly, hypothalamic hamartoma, and the other features of Pallister-Hall syndrome.


    Pallister-Hall syndrome is inherited in an autosomal dominant pattern.This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits a mutation in the GLI3 gene from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family

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    its new nd nice 4me

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    Exclamation Pallister-Hall syndrome - Addon

    The primary feature of Pallister-Hall syndrome is the hypothalamic hamartoma. Other major manifestations of the syndrome include polydactyly, dysplastic nails, bifid epiglottis, imperforate anus, renal anomalies, pituitary dysplasia, and hypopituitarism.


    In familial cases, Pallister-Hall syndrome has been noted to be inherited in an autosomal dominant pattern with variable expressivity. It has been linked with a mutation to a zinc finger transcription factor gene, GLI3, which resides on chromosome 7p13 in some inherited probands.Mutations to the GLI3 gene have been associated also with Greig cephalopolysyndactyly syndrome.
    Histologic examination of the hypothalamic lesions in patients who died as neonates demonstrated primitive germinal cells, which indicated a neoplastic potential. For this reason, the term hypothalamic hamartoblastoma was assigned initially to these tumors. Subsequent pathologic examination of tumors from older patients with Pallister-Hall syndrome, however, has revealed disordered arrangements of large mature-appearing neurons admixed with astrocytes and minimal white matter.The white matter has shown varying degrees of myelination. Because these tumors have a more mature histologic appearance and benign clinical course, they are thought now to be hypothalamic hamartomas. The previous description of undifferentiated germinal cells within these tumors is felt now to represent the hamartomatous equivalent of the neonatal germinal matrix .
    Disruption of pituitary development from the hypothalamic hamartoma can result in endocrine abnormalities, which were a prominent feature in the initial description of Pallister-Hall syndrome. The main cause of mortality in the first-described cases was acute adrenal insufficiency associated with panhypopituitarism .A wide spectrum of pituitary abnormalities has been reported subsequently ranging from asymptomatic individuals to panhypopituitarism .Hypothyroidism, microphallus, and cryptorchidism have been reported also.

    Craniofacial abnormalities are felt to be secondary to disruption of midline development by the hypothalamic hamartoma. These include a short nose with flat nasal bridge, low-set and posteriorly angulated ears, cleft palate, cleft uvula, buccal frenula, bifid epiglottis, and cleft larynx.

    Limb abnormalities include polydactyly, short limbs, syndactyly, and nail dysplasia involving the toes and fingers. Other genitourinary abnormalities described in addition to microphallus and cryptorchidism are renal hypoplasia or agenesis and renal ectopia. Reported congenital heart defects include patent ductus arteriosus, ventricular septal defect, endocardial cushion defect, mitral and aortic valve defects, and proximal aortic coarctation. Pulmonary segmentation anomalies are associated also with Pallister-Hall syndrome

    Other conditions with overlapping features include Ellis-van Crevald syndrome (congenital heart defects, polydactyly, multiple frenula, and natal teeth), Smith-Lemli-Opitz syndrome (polydactyly and various CNS anomalies), oral-facial-digital syndrome type VI (autosomal recessive, polydactyly, tongue hamartomas, and cerebellar vermis hypoplasia), Kaufman-McKusick syndrome (autosomal recessive, hydrometrocolpos, polydactyly, and congenital heart defects), and Grieg cephalopolysyndactyly syndrome (autosomal dominant, polydactyly, and craniofacial abnormalities) .As previously discussed, the hypothalamic hamartoma of Pallister-Hall syndrome is the key feature in differentiating it from these aforementioned entities.

    On MR imaging, the classic hypothalamic (tuber cinereum) hamartoma is noncalcified and nonenhancing, and is homogeneously isointense to gray matter on T1-weighted images, isointense to mildly hyperintense on proton density–weighted images, and often hyperintense on T2-weighted images. These imaging findings are fairly characteristic and are helpful in differentiating the hypothalamic hamartoma from the more common suprasellar lesions such as craniopharyngioma and hypothalamic/opticochiasmatic glioma seen in children. Craniopharyngiomas are usually heterogeneous with cystic and solid enhancing components as well as focal calcifications. The cystic areas have a variable appearance on MR images but often have increased signal on T1-weighted images. Gliomas have variable enhancement, are hypointense to isointense on T1-weighted images, hyperintense on T2-weighted images, and are usually more heterogeneous in appearance than hamartomas. This particular case is interesting both for the unusually large size of the tumor and for the apparent MR findings of prominent white matter tracts coursing throughout the tumor, suggesting a relatively mature histologic course.

    The importance of recognizing Pallister-Hall syndrome should be stressed not only for clinical management but also for future genetic counseling. In this case, the proper diagnosis prevented an unnecessary neurosurgical procedure for this patient. Clinical management of these patients should include endocrinologic evaluation of the hypothalamic-pituitary axis, ophthalmologic evaluation with visual-field testing, serial MR imaging for tumor progression, and a dedicated search for associated anomalies .It is recommended also that the parents of affected individuals be screened for asymptomatic hypothalamic hamartomas with cranial MR imaging.


    FIG 1. Single image from laryngoscopy demonstrates large midline cleft (black arrow) through the epiglottis (white arrows).

    FIG 2. Anteroposterior conventional radiograph of left hand shows polydactyly with hypoplastic accessory metacarpal, proximal, and mid phalange between fourth and fifth digits.



    FIG 3. Sagittal T1-weighted (580/14/2 [TR/TE/excitations]) MR image demonstrates large sellar and suprasellar mass extending over and through dorsum sella and into pontine cistern. The infundibulum is anteriorly displaced and pituitary (arrow) is compressed. Posterior displacement of pons and midbrain with superior displacement of third ventricle is visible.



    FIG 4. A and B, Axial (A) and coronal (B) T2-weighted (2500/90/1) MR images show heterogeneous appearance to tumor with mixed signal intensities equivalent to white and gray matter of remaining normal brain.

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    Nice article dr gaurav.!

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    Quote Originally Posted by dr_kals View Post
    Nice article dr gaurav.!
    Thanks dr_kals....but didn't get better article for this topic...quite a interesting topic

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    Default More graphics



    Reference: Ann Haskins Olney, Peg Kolodziej. (1998). Pallister-Hall syndrome. Ear, Nose & Throat Journal, 77(5), 370
    for reading!

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    Good work bladder.!! Really appriciated.!!

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