Facial palsy and cranial nerve abnormalities in CHARGE association

Asymmetric crying facies in an elderly, when a facial asymmetry is not a facial paralysis but a marker of possible congenital malformations: case report and review of the literature

BACKGROUND

Facial asymmetry when crying at birth (then called asymmetric crying facies or ACF) or when smiling or speaking loudly in adulthood is the consequence of the agenesis or hypoplasia of the muscle of one of the labial commissures. This developmental disorder of complex mechanism is well known by pediatricians to be a warning sign for underlying developmental disorders of variable severity.

CASE REPORT

An 80-year-old man with medical history of renal agenesis was hospitalized for a transient motor deficit of the right face and arm revealing a lacunar stroke. Clinical examination showed an isolated left facial asymmetry upon smiling or talking out loud which had been known since childhood and was not related to the stroke, leading to the diagnosis of ACF. Cardiac ultrasound revealed a patent foramen. Chromosomal investigations could not be performed.

DISCUSSION AND CONCLUSION

ACF is a rare disorder that may conceal associated congenital disorders such as heart, skeletal, or renal malformations. Its causing mechanisms are to this day still poorly understood but may include a genetic component as shown by familial cases and the identification of 22q11.2 deletions or trisomy 18 in some patients. Knowledge of this disorder seems highly relevant for adult neurologists, first because of the differential diagnosis with facial palsy, but mostly because it will allow them to screen patients for other congenital disorders such as heart malformations. Conversely, cardiologists and cardiac surgeon may search for an ACF when faced with a patient with a congruent heart defect.

Relative Preservation of Superior Semicircular Canal Architecture in CHARGE Syndrome

OBJECTIVES

(1) Describe common patterns of semicircular canal (SCC) anomalies in CHARGE syndrome (CS) and (2) recognize that in CS, the architecture of the superior SCC may be relatively preserved.

STUDY DESIGN

This is a retrospective review of temporal bone imaging studies.

SETTING

Quaternary care center.

SUBJECTS AND METHODS

A sample of 37 patients with CS. All subjects met clinical diagnostic criteria for CS. The presence/absence of anomalies of the middle ear, mastoid, temporal bone venous anatomy, inner ear, and internal auditory canal was recorded. Anomalies of each SCC were considered separately and by severity (normal, dysplasia, aplasia).

RESULTS

Thirty-seven subjects (74 temporal bones) were reviewed. Thirty-four (92.0%) patients demonstrated bilateral SCC anomalies. Three (8.0%) had normal SCCs. In patients with SCC anomalies, all canals demonstrated bilateral abnormalities. Thirty-two (86.5%) patients had bilateral horizontal SCC aplasia. These 32 patients also demonstrated posterior SCC aplasia in at least 1 ear. Of 74 temporal bones, 37 (50.0%) had superior SCC dysplasia. All dysplastic superior SCCs showed preservation of the anterior limb. Complete superior SCC aplasia was found in 28 (37.8%) temporal bones.

CONCLUSION

SCC anomalies occur with high frequency in CS. Complete absence of the horizontal and posterior canals is typical and usually bilateral. By contrast, the superior SCC often demonstrates relative preservation of the anterior limb.

Role of Chd7 in zebrafish: a model for CHARGE syndrome

CHARGE syndrome is caused by mutations in the CHD7 gene. Several organ systems including the retina, cranial nerves, inner ear and heart are affected in CHARGE syndrome. However, the mechanistic link between mutations in CHD7 and many of the organ systems dysfunction remains elusive. Here, we show that Chd7 is required for the organization of the neural retina in zebrafish. We observe an abnormal expression or a complete absence of molecular markers for the retinal ganglion cells and photoreceptors, indicating that Chd7 regulates the differentiation of retinal cells and plays an essential role in retinal cell development. In addition, zebrafish with reduced Chd7 display an abnormal organization and clustering of cranial motor neurons. We also note a pronounced reduction in the facial branchiomotor neurons and the vagal motor neurons display aberrant positioning. Further, these fish exhibit a severe loss of the facial nerves. Knock-down of Chd7 results in a curvature of the long body axis and these fish develop irregular shaped vertebrae and have a reduction in bone mineralization. Chd7 knockdown also results in a loss of proper segment polarity illustrated by flawed efnb2a and ttna expression, which is associated with later vascular segmentation defects. These critical roles for Chd7 in retinal and vertebral development were previously unrecognized and our results provide new insights into the role of Chd7 during development and in CHARGE syndrome pathogenesis.

Abnormal basiocciput development in CHARGE syndrome

BACKGROUND AND PURPOSE

The causative gene of the common congenital malformation referred to as CHARGE syndrome is CHD7. Affected individuals often undergo head and neck imaging to assess abnormalities of the olfactory structures, hypothalamus-pituitary axis, and inner ear. We encountered a few children with severe hypoplasia of the basiocciput during a radiologic assessment of patients with CHARGE syndrome. To our knowledge, this anomaly has not been reported. Our purpose was to evaluate the incidence and severity of this anomaly in this syndrome.

MATERIALS AND METHODS

Sagittal MR images of 8 patients with CHARGE syndrome were retrospectively reviewed by 2 radiologists who consensually evaluated the status of the basiocciput of the patients with CHARGE syndrome, as either normal or hypoplastic; and associated anomalies, which include basilar invagination, Chiari type I malformation, and syringomyelia, as either present or absent. The length between the basion (Ba) and the endo-sphenobasion (Es) and between the basion and the exo-sphenobasion (Xs) was measured on midsagittal MR images of the 8 patients and 70 age-matched controls. We searched for trends related to age in the length of Ba-Es and Ba-Xs of the control children by using a matched t test.

RESULTS

Basioccipital hypoplasia was identified in 7 of the 8 patients with CHARGE syndrome and was severe in 6. Of those, 5 had associated basilar invagination and 1 had Chiari type I malformation with syringomyelia.

CONCLUSIONS

Basioccipital hypoplasia and basilar invagination are prevalent in patients with CHARGE syndrome.

Multiple mutations in mouse Chd7 provide models for CHARGE syndrome

Mouse ENU mutagenesis programmes have yielded a series of independent mutations on proximal chromosome 4 leading to dominant head-bobbing and circling behaviour due to truncations of the lateral semicircular canal of the inner ear. Here, we report the identification of mutations in the Chd7 gene in nine of these mutant alleles including six nonsense and three splice site mutations. The human CHD7 gene is known to be involved in CHARGE syndrome, which also shows inner ear malformations and a variety of other features with varying penetrance and appears to be due to frequent de novo mutation. We found widespread expression of Chd7 in early development of the mouse in organs affected in CHARGE syndrome including eye, olfactory epithelium, inner ear and vascular system. Closer inspection of heterozygous mutant mice revealed a range of defects with reduced penetrance, such as cleft palate, choanal atresia, septal defects of the heart, haemorrhages, prenatal death, vulva and clitoral defects and keratoconjunctivitis sicca. Many of these defects mimic the features of CHARGE syndrome. There were no obvious features of the gene that might make it more mutable than other genes. We conclude that the large number of mouse mutants and human de novo mutations may be due to the combination of the Chd7 gene being a large target and the fact that many heterozygous carriers of the mutations are viable individuals with a readily detectable phenotype.

Autism associated with conditions characterized by developmental errors in early embryogenesis: a mini review

Autism is a complex developmental disorder without an established single etiology but with significant contributions from genetic studies, functional research, and neuropsychiatric and neuroradiologic investigations. The purpose of this paper is to review the findings in five studies involving individuals manifesting the characteristic findings of autism spectrum disorder associated with malformations and dysfunctions known to result from early embryogenic defects. These investigations include two associated with teratogens (thalidomide embryopathy, Mobius sequence with misoprostol) and three (most Mobius sequence cases, CHARGE association, Goldenhar syndrome) with no known etiology. These studies suggest that early embryonic development errors often involving cranial nerve palsies, internal and external ear malformations, ophthalmologic anomalies, and a variety of systemic malformations may be associated with autism spectrum disorders statistically more frequently than expected in a normal population. Although the exact time of developmental insult for each condition cannot be identified, the evidence is that it may occur as early as week 4 to 6+ of embryogenesis.

Otological manifestations of CHARGE association

The combined findings of abnormalities of the incus and stapes, absence of the oval window, absence of the stapedius muscle (with absent pyramidal eminence and tympanic sinus in most cases), and abnormalities of different parts of the inner ear (dysplastic cochlea, hypoplastic or dysplastic vestibule, and absent semicircular canals) are characteristic of the CHARGE association. Computed tomography and magnetic resonance imaging using 1-mm-thick contiguous slices proved useful in demonstrating the broad spectrum of temporal bone abnormalities in patients with the CHARGE association.

CHARGE syndrome: report of 47 cases and review

The acronym CHARGE refers to a syndrome of unknown cause. Here we report on 47 CHARGE patients evaluated for the frequency of major anomalies, namely coloboma (79%), heart malformation (85%), choanal atresia (57%), growth and/or mental retardation (100%), genital anomalies (34%), ear anomalies (91%), and/or deafness (62%). In addition, we comment on anomalies observed very frequently in neonates and infants with the CHARGE syndrome, including, minor facial anomalies, neonatal brain stem dysfunction with cranial nerve palsy, and, mostly, internal ear anomalies such as semicircular canal hypoplasia that were found in each patient that could be tested. We propose several criteria for poor survival including male gender, central nervous system and/or oesophageal malformations, and bilateral choanal atresia. No predictive factor regarding developmental prognosis could be identified in our series. A significantly higher mean paternal age at conception together with concordance in monozygotic twins and the existence of rare familial cases support the role of genetic factors such as de novo mutation of a dominant gene or subtle sub-microscopic chromosome rearrangement. Finally, the combination of malformations in CHARGE syndrome strongly supports the view that this multiple congenital anomalies/mental retardation syndrome is a polytopic developmental field defect involving the neural tube and the neural crests cells.

CHARGE association: an update and review for the primary pediatrician

CHARGE association is a nonrandom pattern of congenital anomalies that occurs together more frequently than one would expect on the basis of chance. This common multiple anomaly condition has an estimated prevalence of 1:10,000. The number of children diagnosed with CHARGE association is increasing, owing presumably to greater awareness of this condition and advances in the care of complex, chronically ill children, resulting in improved survival and outcome. This review of CHARGE association presents diagnostic criteria that may define a concise, recognizable syndrome with a single pathogenetic basis. This review also summarizes our current understanding of the management for this complex and chronic multiple congenital anomaly condition and discusses the pathogenetic basis for this condition.

Clinical manifestations of CHARGE Association

The clinical literature regarding CHARGE Association is mostly retrospective in nature and deals largely with non-auditory issues related to the care and management of these patients with multisystem involvements. In this paper, we describe the clinical findings in 24 patients evaluated in the Division of Audiology and Electrophysiology at the University of Michigan Medical Center from 1983 to 1993. We report on the clinical manifestations of CHARGE Association in these patients with particular attention paid to their audiologic status. We discuss the relationships between auditory, ear, and craniofacial anomalies. Our review of these previously unreported cases suggests the following: (1) a variety of audiologic outcomes is possible, however, if a sensorineural or mixed hearing loss exists, it tends to be severe in degree; (2) progressive hearing loss does not appear to occur, but recurring otitis media is a probable confounding factor in the early identification of hearing loss; (3) congenital unresolved facial weakness may serve as a reliable predictor of sensorineural hearing loss; and (4) amplification use may be poor due to a number of factors. We hope to offer guidance to the professionals from assorted disciplines who participate in the care of these children.