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Background: Facial palsy manifests as unilateral or bilateral weakness and inability to move some of the facial muscles. The aetiology may be different including idiopathic, trauma, infections or brain tumours or it can be associated with chronic neurological diseases. For instance, in recurrent migraine, an increased risk of idiopathic facial palsy (often unilateral) has been observed. Migraine is a neurovascular disorder characterized by mild to severe intensity of headaches, often associated with neuro-ophthalmological symptoms., Methods: A family is reported where five members were affected by facial palsy associated with other clinical features including migraine, diplopia, facial swelling, eye conjunctivitis following a vertical transmission. Whole exome sequencing was performed in three members (two affected and one healthy) in order to identify potential variants causative of their phenotype., Results: A missense variant c.304G>A was found leading to the p.(Ala102Thr) substitution in the TRPM8 gene, previously related to migraine by genome wide association studies. This variant was classified as deleterious by several predictor tools, and the mutant residue was predicted to alter the protein structure in terms of flexibility and interactions with the surrounding residues., Conclusion: These findings suggest that TRPM8 could be a new causative gene further linking migraine and recurrent facial palsy., (© 2023 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Hereditary congenital facial paresis type 1 (HCFP1) is an autosomal dominant disorder of absent or limited facial movement that maps to chromosome 3q21-q22 and is hypothesized to result from facial branchial motor neuron (FBMN) maldevelopment. In the present study, we report that HCFP1 results from heterozygous duplications within a neuron-specific GATA2 regulatory region that includes two enhancers and one silencer, and from noncoding single-nucleotide variants (SNVs) within the silencer. Some SNVs impair binding of NR2F1 to the silencer in vitro and in vivo and attenuate in vivo enhancer reporter expression in FBMNs. Gata2 and its effector Gata3 are essential for inner-ear efferent neuron (IEE) but not FBMN development. A humanized HCFP1 mouse model extends Gata2 expression, favors the formation of IEEs over FBMNs and is rescued by conditional loss of Gata3. These findings highlight the importance of temporal gene regulation in development and of noncoding variation in rare mendelian disease., (© 2023. The Author(s).)

Microtubules are formed from heterodimers of alpha- and beta-tubulin, each of which has multiple isoforms encoded by separate genes. Pathogenic missense variants in multiple different tubulin isoforms cause brain malformations. Missense mutations in TUBB3, which encodes the neuron-specific beta-tubulin isotype, can cause congenital fibrosis of the extraocular muscles type 3 (CFEOM3) and/or malformations of cortical development, with distinct genotype-phenotype correlations. Here, we report fourteen individuals from thirteen unrelated families, each of whom harbors the identical NM_006086.4 (TUBB3):c.785G>A (p.Arg262His) variant resulting in a phenotype we refer to as the TUBB3 R262H syndrome. The affected individuals present at birth with ptosis, ophthalmoplegia, exotropia, facial weakness, facial dysmorphisms, and, in most cases, distal congenital joint contractures, and subsequently develop intellectual disabilities, gait disorders with proximal joint contractures, Kallmann syndrome (hypogonadotropic hypogonadism and anosmia), and a progressive peripheral neuropathy during the first decade of life. Subsets may also have vocal cord paralysis, auditory dysfunction, cyclic vomiting, and/or tachycardia at rest. All fourteen subjects share a recognizable set of brain malformations, including hypoplasia of the corpus callosum and anterior commissure, basal ganglia malformations, absent olfactory bulbs and sulci, and subtle cerebellar malformations. While similar, individuals with the TUBB3 R262H syndrome can be distinguished from individuals with the TUBB3 E410K syndrome by the presence of congenital and acquired joint contractures, an earlier onset peripheral neuropathy, impaired gait, and basal ganglia malformations., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Introduction: Congenital facial weakness (CFW) can result from facial nerve paresis with or without other cranial nerve and systemic involvement, or generalized neuropathic and myopathic disorders. Moebius syndrome is one type of CFW. In this study we explored the utility of electrodiagnostic studies (EDx) in the evaluation of individuals with CFW., Methods: Forty-three subjects enrolled prospectively into a dedicated clinical protocol and had EDx evaluations, including blink reflex and facial and peripheral nerve conduction studies, with optional needle electromyography., Results: MBS and hereditary congenital facial paresis (HCFP) subjects had low-amplitude cranial nerve 7 responses without other neuropathic or myopathic findings. Carriers of specific pathogenic variants in TUBB3 had, in addition, a generalized sensorimotor axonal polyneuropathy with demyelinating features. Myopathic findings were detected in individuals with Carey-Fineman-Ziter syndrome, myotonic dystrophy, other undefined myopathies, or CFW with arthrogryposis, ophthalmoplegia, and other system involvement., Discussion: EDx in CFW subjects can assist in characterizing the underlying pathogenesis, as well as guide diagnosis and genetic counseling., (© 2021 Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Bell's palsy is the most common cause of unilateral facial paralysis and is defined as an idiopathic and acute inability to control movements of the facial muscles on the affected side. While the pathogenesis remains unknown, previous studies have implicated post-viral inflammation and resulting compression of the facial nerve. Reported heritability estimates of 4-14% suggest a genetic component in the etiology and an autosomal dominant inheritance has been proposed. Here, we report findings from a meta-analysis of genome-wide association studies uncovering the first unequivocal association with Bell's palsy (rs9357446-A; P = 6.79 × 10 -23 , OR = 1.23; N cases  = 4714, N controls  = 1,011,520). The variant also confers risk of intervertebral disc disorders (P = 2.99 × 10 -11 , OR = 1.04) suggesting a common pathogenesis in part or a true pleiotropy.

We report a patient with early onset facioscapulohumeral muscular dystrophy type 1 (FSHD1) who was not diagnosed until 48 years of age. She developed progressive facial diplegia from the age of 4-5 years followed by limb muscle weakness. Motor nerve conduction was normal, myopathic changes were seen electromyographically. Creatine kinase activity was mildly increased at the beginning. Muscle biopsy at 8 years suggested a neurogenic pattern, a second biopsy at age 30 was chronic myopathic with fibre calibre variation. The patient lost the ability to walk at age 44. When last seen she had total facial diplegia, no active movements in her limbs, mild kyphoscoliosis and a rigid thoracic spine. Molecular studies revealed a shortened D4Z4 fragment confirming the diagnosis FSHD1. Her family history was unremarkable, suggesting a de novo mutation. This report is to illustrate the evolving phenotype of early onset FSHD1 with predominating facial palsy., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Congenital facial palsy is unilateral or bilateral facial nerve palsy at birth due to genetic or different pathogenic factors. It can be divided into syndromic type and non-syndromic type according to its accompanying symptom. The pathogeny and symptom of each type are different, in part with genetic heterogeneity. Congenital facial palsy cannot recover spontaneously. Different types of congenital facial palsy have different treatment schemes. The treatment is significant to the improvement of life quality and physical and mental development of children with congenital facial palsy.

Mutations in the chromatin regulator gene BRPF1 were recently associated with the Intellectual Developmental Disorder With Dysmorphic Facies And Ptosis (IDDDFP). Up till now, clinical data of 22 patients are reported. Besides intellectual disability (ID), ptosis and blepharophimosis are frequent findings, with refraction problems, amblyopia and strabism as other reported ophthalmological features. Animal studies indicate BRPF1 as an important mediator in brain development. However, only 5 of 22 previously reported patients show structural brain abnormalities. We report on an additional patient harboring a novel de novo nonsense mutation p.(Glu219*) in BRPF1. He presented with ID, bilateral iris colobomas, facial nerve palsy and severe hypoplasia of the corpus callosum. Our findings support previous findings of brain abnormalities in BRPF1-mutations and indicates coloboma and facial nerve palsy as possible additional features of IDDDFP syndrome., (Copyright © 2019. Published by Elsevier Masson SAS.)

Purpose: To characterize new molecular factors implicated in a hereditary congenital facial paresis (HCFP) family and otosclerosis., Methods: We performed exome sequencing in a four-generation family presenting nonprogressive HCFP and mixed hearing loss (HL). MEPE was analyzed using either Sanger sequencing or molecular inversion probes combined with massive parallel sequencing in 89 otosclerosis families, 1604 unrelated affected subjects, and 1538 unscreened controls., Results: Exome sequencing in the HCFP family led to the identification of a rare segregating heterozygous frameshift variant p.(Gln425Lysfs*38) in MEPE. As the HL phenotype in this family resembled otosclerosis, we performed variant burden and variance components analyses in a large otosclerosis cohort and demonstrated that nonsense and frameshift MEPE variants were significantly enriched in affected subjects (p = 0.0006-0.0060)., Conclusion: MEPE exerts its function in bone homeostasis by two domains, an RGD and an acidic serine aspartate-rich MEPE-associated (ASARM) motif inhibiting respectively bone resorption and mineralization. All variants associated with otosclerosis are predicted to result in nonsense mediated decay or an ASARM-and-RGD-truncated MEPE. The HCFP variant is predicted to produce an ASARM-truncated MEPE with an intact RGD motif. This difference in effect on the protein corresponds with the presumed pathophysiology of both diseases, and provides a plausible molecular explanation for the distinct phenotypic outcome.

Congenital cranial dysinnervation disorders (CCDDs) comprise a heterogeneous spectrum of diseases characterized by congenital, non-progressive impairment of eye, eyelid and/or facial movements including Möbius syndrome, Duane retraction syndrome, congenital ptosis, and congenital fibrosis of the extraocular muscles. Over the last 20 years, several CCDDs have been identified as neurodevelopmental disorders that are caused by mutations of genes involved in brain and cranial nerve development, e.g. KIF21A and TUBB3 that each plays a pivotal role for microtubule function. In a five-generation pedigree, we identified a heterozygous mutation of TUBB6, a gene encoding a class V tubulin which has not been linked to a human hereditary disease so far. The missense mutation (p.Phe394Ser) affects an amino acid residue highly conserved in evolution, and co-segregates with a phenotype characterized by congenital non-progressive bilateral facial palsy and congenital velopharyngeal dysfunction presenting with varying degrees of hypomimia, rhinophonia, impaired gag reflex and bilateral ptosis. Expression of the mutated protein in yeast led to an impaired viability compared to wildtype cells when exposed to the microtubule-poison benomyl. Our findings enlarge the spectrum of tubulinopathies and emphasize that mutations of TUBB6 should be considered in patients with congenital non-progressive facial palsy. Further studies are needed to verify whether this phenotype is indeed part of the CCDD spectrum., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Moebius syndrome is characterized by congenital unilateral or bilateral facial and abducens nerve palsies (sixth and seventh cranial nerves) causing facial weakness, feeding difficulties, and restricted ocular movements. Abnormalities of the chest wall such as Poland anomaly and variable limb defects are frequently associated with this syndrome. Most cases are isolated; however, rare families with autosomal dominant transmission with incomplete penetrance and variable expressivity have been described. The genetic basis of this condition remains unknown. In a cohort study of nine individuals suspected to have Moebius syndrome (six typical, three atypical), we performed whole-exome sequencing to try to identify a commonly mutated gene. Although no such gene was identified and we did not find mutations in PLXND1 and REV3L , we found a de novo heterozygous mutation, p.E410K, in the gene encoding tubulin beta 3 class III ( TUBB3 ), in an individual with atypical Moebius syndrome. This individual was diagnosed with near-complete ophthalmoplegia, agenesis of the corpus callosum, and absence of the septum pellucidum. No substantial limb abnormalities were noted. Mutations in TUBB3 have been associated with complex cortical dysplasia and other brain malformations and congenital fibrosis of extraocular muscles type 3A (CFEOM3A). Our report highlights the overlap of genetic etiology and clinical differences between CFEOM and Moebius syndrome and describes our approach to identifying candidate genes for typical and atypical Moebius syndrome.

Hereditary congenital facial paresis (HCFP) is characterized by isolated dysfunction of the facial nerve (CN VII) due to congenital cranial dysinnervation disorders. HCFP has genetic heterogeneity and HOXB1 is the first identified gene. We report the clinical, radiologic and molecular investigations of three patients admitted for HCFP in a large consanguineous Turkish family. High-throughput sequencing and Sanger sequencing of all patients revealed a novel homozygous mutation p.Arg230Trp (c.688C>T) within the HOXB1 gene. The report of the mutation brings the total number of HOXB1 mutations identified in HCFP to four. The results of this study emphasize that in individuals with congenital facial palsy accompanied by hearing loss and dysmorphic facial features, HOXB1 mutation causing HCFP should be kept in mind., (Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Hereditary congenital facial paresis (HCFP) belongs to the congenital cranial dysinnervation disorders. HCFP is characterized by the isolated dysfunction of the seventh cranial nerve and can be associated with hearing loss, strabismus, and orofacial anomalies. Möbius syndrome shares facial palsy with HCFP, but is additionally characterized by limited abduction of the eye(s). Genetic heterogeneity has been documented for HCFP as one locus mapped to chromosome 3q21-q22 (HCFP1) and a second to 10q21.3-q22.1 (HCFP2). The only known causative gene for HCFP is HOXB1 (17q21; HCFP3), encoding a homeodomain-containing transcription factor of the HOX gene family, which are master regulators of early developmental processes. The previously reported HOXB1 mutations change arginine 207 to another residue in the homeodomain and alter binding capacity of HOXB1 for transcriptional co-regulators and DNA. We performed whole exome sequencing in HCFP-affected individuals of a large consanguineous Moroccan family. The homozygous nonsense variant c.66C>G/p.(Tyr22*) in HOXB1 was identified in the four patients with HCFP and ear malformations, while healthy family members carried the mutation in the heterozygous state. This is the first disease-associated HOXB1 mutation with a likely loss-of-function effect suggesting that all HOXB1 variants reported so far also have severe impact on activity of this transcriptional regulator. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Congenital cranial dysinnervation disorders (CCDD) encompass a number of related conditions and includes Duane syndrome, congenital fibrosis of the external ocular muscles, Möbius syndrome, congenital ptosis and hereditary congenital facial paresis. These are congenital disorders where the primary findings are non-progressive and are caused by developmental abnormalities of cranial nerves/nuclei with primary or secondary dysinnervation. Several CCDD genes have been found, which enhance our understanding of the mechanisms involved in brain stem development and axonal guidance., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Moebius syndrome (MBS) is a rare congenital disorder characterized by rhombencephalic mal development, mainly presenting with facial palsy with limited gaze abduction. Most cases are sporadic, possibly caused by a combination of environmental and genetic factors; however, no proven specific associations have been yet established. Hereditary congenital facial palsy (HCFP) is an autosomal dominant congenital dysinnervation syndrome, recognizable by the isolated dysfunction of the seventh cranial nerve. Mutant mice for Hoxb1 were reported to present with facial weakness, resembling MBS. Recently a homozygous mutation altering arg5 residue of HOXB1 homeodomain into cys5 was identified in two families with HCFP. We screened 95 sporadic patients diagnosed as MBS or HCFP for mutations in HOXB1. A novel homozygous alteration was identified in one HCFP case, affecting the same residue, resulting to his5. In silico protein analysis predicted stronger HOXB1-DNA binding properties for his5 than cys5 that resulted to milder phenotype. It should be noted that, inclusive of the previous report, only two mutations revealed in HOXB1 associated with HCFP involved the same amino acid arg5 in HOXB1 residing in HOXB1-DNA-PBX1 ternary complex., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3 weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1). It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans.

Congenital myasthenic syndromes are inherited disorders caused by various defects in neuromuscular transmission. Although the typical presentation is fatigable weakness with prominent cranial involvement, neonates can lack these hallmark manifestations, and in those with choline acetyltransferase gene mutations, basal electrophysiological testing can yield negative findings. The authors report the case of a male infant presenting at birth with oculomotor and bulbofacial weakness, hypotonia, clubfoot, and severe respiratory insufficiency. Electromyography showed myogenic signs, and basal repetitive nerve stimulation yielded negative findings. Since age 6 months, the infant had progressively improved, acquiring autonomous respiration. Prolonged subtetanic repetitive nerve stimulation disclosed a marked decremental response compatible with suspected congenital myasthenic syndrome with episodic apnea. Genetic testing identified 2 novel choline acetyltransferase mutations (R470X, F580C). Keeping a high clinical suspicion of this rare condition and undertaking early comprehensive electrophysiological assessments including prolonged repetitive nerve stimulation (10 Hz for 5 minutes) can expedite the diagnosis.

We described a case of Gitelman syndrome. A 56-year-old healthy man presented with facial paralysis. Initial laboratory tests revealed hypokalemia. Despite potassium supplements, kaliemia remains at low levels. Further investigations showed urinary potassium wasting, hypomagnesemia and hypocalciuria. Diagnosis of Gitelman syndrome has been confirmed by molecular diagnosis with identification of a composite heterozygote mutation on SLC12A3 gene. One of the mutations on exon 1 SCL12A3 gene wasn't yet known. In the patient family, the same genetic disorder has been found in the sister. Treatment and follow up schedule were proposed to patient.

Members of the highly conserved homeobox (HOX) gene family encode transcription factors that confer cellular and tissue identities along the antero-posterior axis of mice and humans. We have identified a founder homozygous missense mutation in HOXB1 in two families from a conservative German American population. The resulting phenotype includes bilateral facial palsy, hearing loss, and strabismus and correlates extensively with the previously reported Hoxb1(-/-) mouse phenotype. The missense variant is predicted to result in the substitution of a cysteine for an arginine at amino acid residue 207 (Arg207Cys), which corresponds to the highly conserved Arg5 of the homeodomain. Arg5 interacts with thymine in the minor groove of DNA through hydrogen bonding and electrostatic attraction. Molecular modeling and an in vitro DNA-protein binding assay predict that the mutation would disrupt these interactions, destabilize the HOXB1:PBX1:DNA complex, and alter HOXB1 transcriptional activity., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Hereditary congenital facial paresis (HCFP) consists of the paralysis or weakness of facial muscles caused by a maldevelopment of the facial branchiomotor (FBM) nucleus and its nerve. Linkage analyses have related this disorder to two loci, HCFP1 and HCFP2, placed respectively in human chromosomes 3q21.2-q22.1 and 10q21.3-q22.1, but the causative genes are still unknown. In this work we aimed to identify which genes from these loci are expressed in the developing hindbrain and particularly in the FBM nucleus. To this end, we retrieved from the ENSEMBL genomic database the list of these genes as well as their respective mouse orthologs. Subsequently we examined their respective expression patterns in the mouse embryo by using the GenePaint gene expression database. As a result of this screening, we found a new gene (Mgll) from the HCFP1 locus that has strong and specific expression in the developing FBM nucleus. In its turn, the HCFP2 locus appeared as a large gene-desert region, flanked by two genes, Reep3, with specific expression in the FBM nucleus, and Lrrtm3, broadly expressed in the brainstem, including the same nucleus. The concurrence of genomic position and neural expression pattern makes these genes new potential candidates for HCFP., (Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.)

Craniotubular dysplasias (CTD) are a heterogeneous group of genetic disorders of skeletal development, whose clinical and etiological classification is still much debated. One of the most common form is the autosomal dominant craniometaphyseal dysplasia (CMD) which is associated with mutation in the ANKH gene. In the literature a few families are reported with CMD phenotype that suggest an autosomal recessive (AR) pattern of inheritance. A candidate locus at 6q21-22 has been mapped in a large inbred Brazilian family, but the gene of the recessive form is still unknown. Our data on a female patient with CMD phenotype, born from healthy first degree cousins and displaying homozygosity for polymorphic markers at the 6q21-22 locus, further support the existence of an AR CMD, expanding its clinical spectrum to a more severe phenotype., (Copyright © 2011 Wiley-Liss, Inc.)

Craniometaphyseal dysplasia (CMD) is a rare genetic disorder with hyperostosis of craniofacial bones and widened metaphyses in long bones. Patients often suffer from neurological symptoms due to obstruction of cranial foramina. No proven treatment is available and the pathophysiology is largely unknown. A Phe377 (TTC(1130-1132)) deletion in exon 9 of the pyrophosphate (PPi) transporter ANK leads to CMD-like features in an Ank(KI/KI) mouse model. Here, we investigated the effects of CMD-mutant ANK on mineralization and bone mass at a cellular level. Ank(KI/KI) osteoblast cultures showed decreased mineral deposition. Expression of bone mineralization regulating genes Mmp13, Ocn, Osx and Phex was reduced in Ank(KI/KI) osteoblasts, while the Fgf23 mRNA level was highly elevated in Ank(KI/KI) calvarial and femoral bones. Since ANK is a known PPi transporter, we examined other regulators of Pi/PPi homeostasis Enpp1 and Tnap. Significantly increased ENPP1 activity may compensate for dysfunctional mutant ANK leading to comparable extracellular PPi levels in Ank(+/+) osteoblasts. Similar to Ank(KI/KI) bone marrow-derived macrophage cultures, peripheral blood cultures from CMD patients exhibited reduced osteoclastogenesis. Cell-autonomous effects in Ank(KI/KI) osteoclasts resulted in disrupted actin ring formation and cell fusion. In addition, Ank(KI/KI) osteoblasts failed to adequately support osteoclastogenesis. Increased bone mass could partially be rescued by bone marrow transplants supporting our hypothesis that reduced osteoclastogenesis contributes at least in part to hyperostosis. We conclude that the Phe377del mutation in ANK causes impaired osteoblastogenesis and osteoclastogenesis resulting in hypomineralization and a high bone mass phenotype.

Facial nerve palsies are uncommon in infants. We report on 10-week-old monozygotic twins, diagnosed with cystic fibrosis by newborn screening, who developed facial palsy and increased intracranial pressure. Cranial imaging and cerebrospinal fluid analysis produced normal results. Levels of serum vitamin A were below normal range. Low levels of vitamin A are associated with facial nerve paralysis, and are at least partly implicated in the development of increased intracranial pressure in infants with cystic fibrosis., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Conclusion: Long-term denervation-induced satellite cells (SCs) deficiency impairs facial muscle regenerative capacity. Delayed reinnervation can reactivate residual SCs to engage in muscle regeneration. However, the underlying mechanism remains to be elucidated., Objective: To evaluate the effects of denervation and delayed reinnervation on SCs in facial muscle., Methods: This was a prospective, randomized, controlled study in the rat facial nerve ligation and delayed decompression model. Animals were divided into denervation, 8-week-delay, and 16-week-delay reinnervation groups. Sham-operated animals served as a control group. Specific markers were used to investigate the differences in SC status, including quiescent (Pax7) and activated (myoD and myogenin) SCs and regenerative myofibers (embryonic myosin heavy chain, eMyHC). Quantitative assessment was performed by real-time PCR and Western blotting., Results: Activated SCs were detected 2-4 weeks after denervation and maintained for 4-8 weeks, accompanied by regenerating myofibers, whereas no SCs were detected beyond 20 weeks post-denervation. The myoD and myogenin up-regulation peaked 6-8 weeks after denervation and declined gradually to normal baseline 12 weeks after denervation. The 8-week-delay reinnervation group showed more activated SCs and regenerating myofibers than the 16-week-delay group, as well as greater up-regulation of myoD and myogenin (p < 0.05), suggesting reactivation of SCs for repair of adjacent fibers.

Hereditary congenital facial paresis is a rare syndrome of isolated facial nerve palsy causing facial asymmetry and ptosis. Most described cases follow an autosomal dominant pattern of inheritance. It differs from Moebius syndrome, which is usually sporadic and associated with the involvement of other cranial nerves, commonly the abducens nerve in addition to orofacial and limb malformations and defects of the musculoskeletal system. We present three patients from the same family with features of congenital hereditary facial paresis. Facial asymmetry and facial weakness were the most remarkable findings. High-resolution imaging showed both facial nerves to be present but symmetrically and markedly hypoplastic with no other structural abnormality in the brainstem. This syndrome has been previously mapped to chromosome 3q21-22 but no gene has been identified as yet.

Background: Joubert syndrome (JS) belongs to the ciliopathies and is a mostly autosomal recessively inherited disease (in the case of OFD1 mutations, JS is an X-linked trait). It is characterised by midbrain-hindbrain malformations with developmental delay, hypotonia and ataxia and a broad spectrum of other facultative findings. The aim of our study was to examine the ophthalmological and neuro-ophthalmological features of JS in our patients and to compare our findings to those of other studies., Methods: In a retrospective study we evaluated the ophthalmological and neuro-ophthalmological findings of 9 consecutive patients who met the diagnostic criteria of JS., Results: All patients had abnormalities of ocular motility, 4/9 used head thrusts to shift gaze (oculomotor apraxia OMA). In 6/8 patients, the optokinetic reflex (OKN) was absent. Furthermore, 8/9 children showed nystagmus, mostly see-saw nystagmus. Manifest strabismus was found in 8/9 while 3/9 had a retinopathy with either abnormal ERG and/or fundus appearance with or without visual impairment. Chorioretinal colobomata were present in 5/9 cases. Two patients showed a unilateral congenital ptosis, one a facial nerve paresis., Conclusions: The early neuro-ophthalmological findings in JS are not pathognonomic, but may lead to the diagnosis of JS. The syndrome should be suspected in patients with nystagmus, especially see-saw nystagmus, and abnormal OKN and/or OMA, and/or colobomata of the fundus, and further paediatric examinations should be initiated., (© Georg Thieme Verlag KG Stuttgart · New York.)

Hyperostosis cranialis interna is a hereditary bone disorder that is characterized by endosteal hyperostosis and osteosclerosis of the calvaria and the skull base (OMIM 144755). The progressive bone overgrowth causes entrapment and dysfunction of cranial nerves I, II, V, VII, and VIII, its first symptoms often presenting during the second decade. This study analyzes the clinical course of 13 affected individuals of three related families (32 individuals). The disorder appears to have an autosomal-dominant transmission pattern. Facial and vestibulocochlear nerve dysfunction are most frequently reported. Surgical decompression of the accessible impaired cranial nerves is advised in the early symptomatic period or even in the presymptomatic period in high-risk individuals., ((c) 2010 Wiley-Liss, Inc.)

CHARGE syndrome [coloboma of the eye, heart defects, atresia of the choanae, retardation of growth and/or development, genital and/or urinary abnormalities, and ear abnormalities (including deafness)] is a genetic disorder characterized by a specific and a recognizable pattern of anomalies. De novo mutations in the gene encoding chromodomain helicase DNA binding protein 7 (CHD7) are the major cause of CHARGE syndrome. Here, we review the clinical features of 379 CHARGE patients who tested positive or negative for mutations in CHD7. We found that CHARGE individuals with CHD7 mutations more commonly have ocular colobomas, temporal bone anomalies (semicircular canal hypoplasia/dysplasia), and facial nerve paralysis compared with mutation negative individuals. We also highlight recent genetic and genomic studies that have provided functional insights into CHD7 and the pathogenesis of CHARGE syndrome., ((c) 2010 Wiley-Liss, Inc.)

Hereditary gelsolin amyloidosis is an autosomally dominantly inherited systemic disease, first described in 1969 by the Finnish ophthalmologist Jouko Meretoja. The estimated number of disease carriers in Finland is almost 1 000, and the disease has subsequently been found in many other countries as well. It's typical initial manifestation is lattice corneal dystrophy, detected at biomicroscopic examination of the eye by the age of 25 to 30 years, followed by slowly progressing cranial neuropathy with bilateral facial palsy, polyneuropathy and generalized cutis laxa. Meretoja's disease is caused by mutations of the gelsolin gene, leading to the production and aberrant processing of variant gelsolin and deposition of its fragments in various tissues in the form of amyloid fibrils.

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative neuromuscular disease that presents with upper and lower motor neuron signs. Although the majority of ALS cases are sporadic, 10% are familial, of which 20%-25% result from mutations in the superoxide dismutase (SOD1) gene. We describe a novel case of SOD1 (A4V)-mediated ALS that presented with lower motor neuron facial diplegia and unilateral vocal cord paralysis. This case expands the phenotypic expression of the A4V mutation.

Moebius syndrome is a rare disorder primarily characterized by congenital facial palsy, frequently accompanied by ocular abduction anomalies, and occasionally associated with orofacial, limb and musculoskeletal malformations. Abnormal development of cranial nerves V through XII underlines the disease pathogenesis. Although some investigations suggested that a causative gene may lie on 13q12.2-q13, there have been no molecular studies targeting possible microdeletions in this region to date. In the present study, we performed microdeletion analyses on 13q12.11-q13 in nine patients, and sequenced three candidate genes in nineteen patients for functional relevance and further resolution of our screening. We ruled out microdeletions on the critical region as a common cause of Moebius syndrome and excluded FGF9, GSH1 and CDX2 genes.

Trisomy 18 is the second most frequent autosomal aneuploidy, after Down's syndrome, in humans. It causes severe congenital abnormalities and mental retardation although phenotypic features, clinical manifestations and prognosis vary occasionally. In cases oftrisomy 18 mosaicism, as in every chromosomal mosaicism, the spectrum of clinical characteristics extends from pathological to almost normal. We report a 9 months old female infant who has been referred to the Genetics Department for evaluation because of unilateral severe microtia, aplasia of mastoid abscess and hemifacial palsy and inlet type intraventricular defect with pulmonary hypertension. Chromosomal investigation revealed a mosaic trisomy 18 [46,XX/47,XX+18] in proportion of 52% and 48% respectively. Microtia/anotia is present in 1.46-4.36/10,000 live births in the general population while the combination of microtia/anotia with trisomy 18 has been reported in very few cases in the relevant bibliography.

An 18-year-old girl had experienced drooping at the left corner of the mouth for several weeks and could not close her left eye. These symptoms improved gradually and spontaneously. She had had a similar experience 2 years earlier; at that time, the right side of the face was affected. Family members reported similar episodes. After excluding Lyme borreliosis and cerebellopontine angle tumour, a diagnosis of idiopathic familial peripheral facial palsy was made. Peripheral facial nerve palsy is commonly seen in children and young adults. Obtaining a family history is helpful in these patients: a positive family history is found in 2.4-28.6% of the cases. In the absence of other symptoms, a diagnosis of idiopathic familial peripheral facial palsy should be considered. The prognosis of these patients is generally good and therapy is usually unnecessary.

The middle ear changes in Sclerosteosis and Van Buchem disease are described. Reduced bone resorption occurs due to faulty activity of the sclerostin molecule, a product of the recently discovered SOST gene in chromosome 17. Syndactyly draws attention to scleroteosis, and a conductive hearing loss develops before age six in both conditions. Acute, repeated attacks of facial palsy, similar to Bell's palsy, are usually the first symptoms in both conditions. Total facial nerve decompression can stop the attacks of facial paralysis. The hearing loss is a problem because new bone formation continues up to age 21. Life saving craniectomy becomes necessary when increased intracranial pressure develops, and this may have to repeated. The sclerostin molecule is now of major interest to the researchers who want to develop a treatment for osteoporosis.

Congenital cranial dysinnervation disorders (CCDDs) are congenital non-progressive, sporadic or familial abnormalities of cranial musculature that result from developmental abnormalities of, or the complete absence of, one or more cranial nerves with primary or secondary muscle dysinnervation. These disorders include vertical disorders of ocular motility, horizontal disorders of ocular motility and disorders with abnormalities of facial motility that were previously referred to as "congenital fibrosis syndromes". The advances in clinical and molecular genetics of congenital cranial dysinnervation disorders are reviewed.

Hereditary congenital facial palsy (HCFP) is an autosomal-dominant disorder consisting of paresis or paralysis of the VIIth (facial) cranial nerve. Genetic heterogeneity for this disorder has been suggested based on linkage analysis in two large Dutch families. Two loci have been identified, one on chromosome 3q21.2-q22.1 (HCFP1) and another on chromosome 10q21.3-q22.1 (HCFP2). Here, we report linkage analysis in a large Pakistani family with dominant congenital facial palsy. A region cosegregating with the disorder was identified on the long arm of chromosome 3, which overlaps with the previously identified HCFP1 locus on chromosome 3q21-q22, thus confirming the involvement of this locus in HCFP. The critical region could be reduced from 5.7 to 3.0 cM between the markers D3S3607 and GDB ID:11524500. In addition, mutation analysis on seven candidate genes: KLF15, FLJ40083, PODXL2, TMCC1, PLEXIN-A1, PLEXIN-D1, and GATA-2, was performed. All genes are located within the critical interval of the Dutch HCFP1 family. The genes PODXL2, PLEXIN-D1, GATA-2, and TMCC1 are also located within the smaller critical interval of the Pakistani HCFP family. Based on the results obtained, all seven genes could be excluded as causative genes in HCFP.

The Finnish type of familial amyloid polyneuropathy due to variant gelsolin is a rare form of familial amyloidosis. The subtype was first described in 1969 and is characterized by progressive cranial neuropathies, corneal lattice dystrophy and distal sensorimotor dysfunction. It is extremely uncommon, with only two families known to be affected in the UK. We discuss the case of a 70-year-old woman who presented with bilateral facial nerve palsies, bilateral sensorineural hearing loss and Finnish type familial hereditary amyloidosis. A literature search of the Medline database (1966-2005) was performed, using the keywords 'amyloid', 'hearing loss' and 'facial palsy'; however, this association appears to be a novel finding. We review the current literature and discuss otorhinolaryngological presentations of amyloidosis.

CHD7 gene mutations were identified in 17 (71%) of 24 children clinically diagnosed to have CHARGE syndrome (C, coloboma of the iris or retina; H, heart defects; A, atresia of the choanae; R, retardation of growth and/or development; G, genital anomalies; and E, ear abnormalities). Colobomata, hearing loss, laryngomalacia, and vestibulo-cochlear defect were prevalent. Molecular testing for CHD7 enables an accurate diagnosis and provides health anticipatory guidance and genetic counseling to families with CHARGE syndrome.

Hereditary congenital facial paresis is a rare autosomal dominantly inherited disorder, in which pathological changes in the brainstem affect the paired facial nuclei and nerves. Previously, the neuropilin-1 protein has been shown to control axon guidance and cell body position of facial motor neurons, and mice with a targeted disruption of neuropilin-1 present with developmental defects of the facial nerve nuclei. Plexin-A1 can function as a signal transducing subunit for the neuronal neuropilin receptor, and its gene is located in the linkage interval for hereditary congenital facial paresis at chromosome 3q21-q22 (MIM601471), making it an excellent candidate gene for this disorder. During mouse embryogenesis, the murine ortholog of plexin-A1 gene showed restricted spatial and temporal expression in the hindbrain, consistent with a role in cell body movement, or axonal guidance during facial nerve development. Sequence analysis of the plexin-A1 gene in patients from the 3q21-q22-linked hereditary congenital facial paresis family revealed several nucleotide changes. However, none of the nucleotide changes led to an amino acid substitution, and reverse transcriptase polymerase chain reaction analysis did not detect aberrant RNA processing. We therefore conclude that it is highly unlikely that Plexin-A1 is involved in the pathogenicity of hereditary congenital facial paresis.

Hereditary congenital facial paresis (HCFP) belongs to the family of congenital cranial dysinnervation disorders and is characterized by an isolated dysfunction of the facial nerve (nVII). While genetic defects have been identified for several members of this disease family, genes underlying congenital facial paresis and Möbius syndrome remain to be discovered. Here we focus on HCFP linked to chromosome 3q21-q22 and identify new candidate genes using expression analysis by means of RNA in situ hybridization during mouse embryogenesis. We selected 28 positional candidates and identified 17 genes with undetectable expression levels during mouse development, ubiquitous expression, or expression in tissues not affected in HCFP. Additionally, 7 genes were excluded by direct sequence or reverse transcription-PCR analysis. The remaining 4 genes (Klf15, Flj40083, Kiaa0779, and Podxl2) were found to be expressed at spatial and temporal positions during mouse development that correlate with HCFP regions in humans, defining these genes as primary candidates in HCFP.

Objective: To characterize the neuropathology of hereditary congenital facial palsy., Methods: The authors compared brainstem pathology of three members of one family with autosomal dominant congenital facial palsy to that in three age-matched controls. The neuropathologic findings of the familial patients were compared with those of patients with Möbius syndrome., Results: The authors observed a marked decrease in the number of neurons in the facial motor nucleus with corresponding small facial nerve remnants. In the patients with congenital facial palsy the number of facial motoneurons ranged between 280 and 1,680 as compared to 5,030 and 8,700 for controls. No signs of neuronal degeneration or necrosis with neuronal loss, gliosis, or calcifications were present. There were no other abnormalities of the rhombencephalon and its associated structures. The corticospinal tracts were fully developed. In contrast, Möbius syndrome is part of a more complex congenital anomaly of the posterior fossa with hypoplasia of the entire brainstem, including the traversing long tracts, with signs of neuronal degeneration and other congenital brain abnormalities., Conclusion: Neuropathologic findings confirm clinical observations that hereditary congenital facial palsy and Möbius syndrome are two different entities with a different pathogenesis.

Congenital unilateral facial palsy has been described as a distinct entity, but there have been few reports of an isolated unilateral familial form, and no reports with supportive neuroimaging. We studied three males from three generations in the same family. Each had a left facial palsy, which was more pronounced with every successive generation. On the House grading scale, the proband, a 9-year-old male, manifested moderately severe facial nerve dysfunction. His 40-year-old father had mild to moderate dysfunction, and his 61-year-old paternal grandfather manifested mild dysfunction. The proband and his father both had abnormal magnetic resonance imaging studies, with the proband's revealing enlargement and enhancement of the tympanic portion of the left facial nerve, and the father's demonstrating enhancement. Temporal bone computed tomography on the 9-year-old confirmed the enlarged left facial nerve. By electromyography/nerve conduction studies there was evidence of a chronic, incomplete, left facial palsy affecting both the father and his son, with substantially lowered compound muscle action potential amplitudes on the left. Congenital unilateral facial palsy spanning three generations with supportive neuroimaging and electromyography/nerve conduction studies has not been previously reported in the literature.