ABSTRACT
Goltz-Gorlin syndrome is a rare X-linked inherited disorder associated with PORCN (porcupine homolog-Drosophila) gene mutation. It primarily affects the skin and its appendages. The characteristic cutaneous features include a blaschko-linear pattern, skin atrophy, pigmentary changes, and telangiectasia. The oral manifestations have been reported in more than half of the affected individuals. The most common oral findings include enamel hypoplasia, hypodontia, supernumerary teeth, microdontia, vertical grooving of the teeth, taurodontism, fusion, and abnormal root morphology reported in sporadic cases. The objective of this case report is to describe the dentofacial characteristics of a middle childhood aged girl with Goltz-Gorlin syndrome.
Subject(s)
Focal Dermal Hypoplasia , Tooth Abnormalities , Tooth, Supernumerary , Child , Female , Humans , Acyltransferases/genetics , Focal Dermal Hypoplasia/complications , Focal Dermal Hypoplasia/genetics , Membrane Proteins/genetics , Mutation , Skin , Tooth Abnormalities/complications , Tooth, Supernumerary/complicationsABSTRACT
We report a case of a 29-year-old woman with subtle partial erythematous, partial hyperpigmented streaks along the Blaschko's lines on the right side of the body since early childhood. Primary DNA results of the skin and blood assay diagnosed focal dermal hypoplasia in mosaic form. The postzygotic mutation in the PORCN gene was only detectable in the affected skin and not in the blood assay. This article illustrates that clinically very discrete hypopigmentation and poikiloderma along Blaschko lines should raise awareness for robust diagnostic analysis in order to recognize this variable multisystem disease and to ensure an appropriate search for extracutaneous abnormalities and human genetic counseling, ideally before pregnancy. Careful correlation of clinical, histological, and genetic features along with close multidisciplinary cooperation of specialists from the fields of human genetics, dermatology, pediatrics, orthopedics and ophthalmology is crucial for final diagnosis, assessment of the prognosis and targeted genetic counseling of affected individuals.
Subject(s)
Acyltransferases , Focal Dermal Hypoplasia , Membrane Proteins , Mosaicism , Humans , Female , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/pathology , Adult , Acyltransferases/genetics , Membrane Proteins/genetics , Mutation , Genetic Predisposition to DiseaseABSTRACT
Goltz-Gorlin syndrome (GGS), also known as focal dermal hypoplasia, is a rare X-linked disorder caused by pathogenic variants in the PORCN gene and characterized by several abnormalities, including skin and limb defects, papillomas in multiple organs, ocular malformations, and mild facial dysmorphism. To date, only approximately 300 cases have been described in the literature. A 16-year-old female patient, born with multiple congenital dysmorphisms consistent with GGS and confirmed by genetic exam, was referred to our outpatient clinic for the workup of a thyroid nodule. A thyroid ultrasound showed a bilateral nodular disease with a 17-mm large hypoechoic nodule in the right lobe. Cytological exam of fine needle aspiration biopsy was suspicious for malignancy. Thus, she underwent total thyroidectomy plus lymphadenectomy of the right central compartment. A histological exam disclosed a papillary thyroid carcinoma (PTC) with lymph node micrometastases. Radioiodine (131-Iodine) therapy was performed. At 3- and 6-month follow-up, the patient did not present either ultrasound or laboratory PTC recurrence. To our knowledge, we report the first case of PTC in a patient with GGS. Since thyroid cancer is rare among children and adolescents, we hypothesize that the PORCN pathogenic variant could be responsible for tumor susceptibility. We also provide an overview of the clinical findings on GGS patients already reported and discuss the possible pathogenetic mechanism that may underlie this rare condition, including the role of PORCN in tumor susceptibility.
Subject(s)
Carcinoma, Papillary , Focal Dermal Hypoplasia , Thyroid Neoplasms , Female , Adolescent , Child , Humans , Thyroid Cancer, Papillary/surgery , Thyroid Cancer, Papillary/drug therapy , Focal Dermal Hypoplasia/complications , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Iodine Radioisotopes/therapeutic use , Carcinoma, Papillary/surgery , Carcinoma, Papillary/drug therapy , Thyroid Neoplasms/complications , Thyroid Neoplasms/surgery , Thyroid Neoplasms/pathology , Acyltransferases , Membrane Proteins/geneticsABSTRACT
Focal dermal hypoplasia (FDH) is a rare X-linked dominant syndrome characterized by streaky cutaneous atrophy in a blaschkoid distribution, skeletal dysplasias, and ocular abnormalities. Here, we report hypospadias and chordee identified in a male patient with molecularly confirmed FDH. This report highlights a new clinical manifestation of male patients with FDH.
Subject(s)
Focal Dermal Hypoplasia , Humans , Male , Focal Dermal Hypoplasia/complications , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , AtrophyABSTRACT
Background: Focal dermal hypoplasia is a genetic disease of multiple systems initially affecting the skin, skeleton, dental, eyes and face with developmental abnormalities and facial dysmorphism. Focal dermal hypoplasia is X-linked dominant disease affecting the ectoderm, mesoderm and endoderm. 95% feature de novo and 90% of these are females. Focal dermal hypoplasia is induced by a mutation in the PORCN gene. Objective: The aim of this article is to present a case of a one-year-old girl child with multi-hypopigmented reticulated atrophic macules and patches grouped in linear mode at the lines of blaschko, skeleton abnormalities, umbilical hernia, developmental delay, hypoplastic nails, syndactyly and lobster claw deformity. Case report: A one-year-old girl child presented to the dermatology clinic with asymptomatic lesions since childhood with no improvement, with multi- hypopigmented skin lesions on the trunk and extremities since birth as linear erosions that heal gradually during few days, leaving peripheral hypopigmentation with hyperpigmentation with anomalies of limbs and nails and delayed development. She was born by normal vaginal delivery and weighed 2.5 kg at birth. None of the family members had such features. She had dental enamel anomaly and partial anodontia in the lower jaw. Sparse hair and partial alopecia (scalp, eyebrows and eyelashes) were recorded. Conclusion: Focal dermal hypoplasia is a congenital skin disease with a unique clinical feature. Thorough examination of the extremities is indicated for early proper genetic counseling and therapy.
Subject(s)
Focal Dermal Hypoplasia , Limb Deformities, Congenital , Female , Humans , Infant , Acyltransferases/genetics , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Limb Deformities, Congenital/pathology , Membrane Proteins/genetics , Mutation , Skin/pathologyABSTRACT
Goltz syndrome is an X-linked dominant, multisystem birth defect due to PORCN mutation. The skin findings follow Blaschko's lines and often show epidermal atrophy and herniation of subcutaneous fatty tissue. Regarding treatment, light sources can offer a good therapeutic option for some manifestations of this rare disease and improve the aesthetic appearance of the skin lesions. We report two new cases of Goltz syndrome in which the cutaneous findings remarkably improved with pulsed dye laser and carbon dioxide laser.
Subject(s)
Focal Dermal Hypoplasia , Laser Therapy , Acyltransferases/genetics , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Humans , Membrane Proteins/genetics , MutationABSTRACT
BACKGROUND: Goltz syndrome (GS) is a X-linked disorder defined by defects of mesodermal- and ectodermal-derived structures and caused by PORCN mutations. Features include striated skin-pigmentation, ocular and skeletal malformations and supernumerary or hypoplastic nipples. Generally, GS is associated with in utero lethality in males and most of the reported male patients show mosaicism (only three non-mosaic surviving males have been described so far). Also, precise descriptions of neurological deficits in GS are rare and less severe phenotypes might not only be caused by mosaicism but also by less pathogenic mutations suggesting the need of a molecular genetics and functional work-up of these rare variants. RESULTS: We report two cases: one girl suffering from typical skin and skeletal abnormalities, developmental delay, microcephaly, thin corpus callosum, periventricular gliosis and drug-resistant epilepsy caused by a PORCN nonsense-mutation (c.283C > T, p.Arg95Ter). Presence of these combined neurological features indicates that CNS-vulnerability might be a guiding symptom in the diagnosis of GS patients. The other patient is a boy with a supernumerary nipple and skeletal anomalies but also, developmental delay, microcephaly, cerebral atrophy with delayed myelination and drug-resistant epilepsy as predominant features. Skin abnormalities were not observed. Genotyping revealed a novel PORCN missense-mutation (c.847G > C, p.Asp283His) absent in the Genome Aggregation Database (gnomAD) but also identified in his asymptomatic mother. Given that non-random X-chromosome inactivation was excluded in the mother, fibroblasts of the index had been analyzed for PORCN protein-abundance and -distribution, vulnerability against additional ER-stress burden as well as for protein secretion revealing changes. CONCLUSIONS: Our combined findings may suggest incomplete penetrance for the p.Asp283His variant and provide novel insights into the molecular etiology of GS by adding impaired ER-function and altered protein secretion to the list of pathophysiological processes resulting in the clinical manifestation of GS.
Subject(s)
Acyltransferases , Focal Dermal Hypoplasia , Membrane Proteins , Acyltransferases/genetics , Female , Focal Dermal Hypoplasia/complications , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Humans , Male , Membrane Proteins/genetics , Mutation , PhenotypeABSTRACT
Mutations in the PORCN gene cause an X-linked dominant condition; focal dermal hypoplasia (FDH), characterized by atrophic skin, pigmented skin lesions in addition to several ocular and skeletal malformations. FDH is rare with around 275 cases reported so far from diverse ethnic groups. Herein, we provide a report of two new patients with FDH from Egypt. In addition to the typical clinical manifestations of the disease, infrequently reported clinical findings in the form of broad metaphysis, bilateral short broad femurs, and dermal sinus over the sacrum were seen in Patient 1 and partial fusion of labia majora, ventral hernia, and bladder extrophy were present in Patient 2. Two heterozygous protein-truncating PORCN mutations were identified in our patients, a known nonsense c.370C>T p.(Arg124Ter) and a novel frameshift c.375delG p.(Ala126HisfsTer3). Segregation analyses confirmed that the two mutations were "de novo" and not inherited from any of the parents. Our study expands the clinical and mutational spectrum of focal dermal hypoplasia and emphasizes the importance of investigating the different body systems and organs for the early management of patients.
Subject(s)
Focal Dermal Hypoplasia , Acyltransferases/genetics , Codon, Nonsense , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Humans , Membrane Proteins/genetics , MutationABSTRACT
Anophthalmia and microphthalmia (A/M) represent severe developmental ocular malformations, corresponding, respectively, to absent eyeball or reduced size of the eye. Both anophthalmia and microphthalmia may occur in isolation or as part of a syndrome. Genetic heterogeneity has been demonstrated, and many genes have been reported to be associated with A/M. The advances in high-throughput sequencing have proven highly effective in defining the molecular basis of A/M. Nevertheless, there are still many patients with unsolved genetic background of the disease, who pose a significant challenge in the molecular diagnostics of A/M. Here we describe a family, with three males affected with the non-syndromic A/M. Whole exome-sequencing performed in Patient 1, revealed the presence of a novel probably pathogenic variant c.734A>G, (p.[Tyr245Cys]) in the PORCN gene. Pedigree analysis and segregation of the identified variant in the family confirmed the X-linked recessive pattern of inheritance. This is the first report of X-linked recessive non-syndromic A/M. Until now, pathogenic variants in the PORCN gene have been identified in the patients with Goltz syndrome, but they were inherited in X-linked dominant mode. The ocular phenotype is the only finding observed in the patients, which allows to exclude the diagnosis of Goltz syndrome.
Subject(s)
Acyltransferases/genetics , Anophthalmos/genetics , Genetic Predisposition to Disease , Membrane Proteins/genetics , Microphthalmos/genetics , Adult , Anophthalmos/complications , Anophthalmos/pathology , Child, Preschool , Exome/genetics , Female , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Genes, Recessive/genetics , Genes, X-Linked/genetics , Genetic Heterogeneity , Humans , Infant , Male , Microphthalmos/complications , Microphthalmos/pathology , Mutation/genetics , Pedigree , Phenotype , Exome SequencingABSTRACT
BACKGROUND: Focal dermal hypoplasia (FDH) is rare X-linked dominant disease characterized by atrophy and linear pigmentation of the skin, split hand/foot deformities and ocular anomalies. FDH is caused by mutations of the Porcupine (PORCN) gene, which encodes an enzyme that catalyzes the palmitoylation of Wnt ligands required for their secretion. High resolution melting analysis (HRM) is a technique that allows rapid, labor-efficient, low-cost detection of genomic variants. In the present study, we report the successful implementation of HRM in the molecular diagnosis of FDH. METHODS: Polymerase chain reaction and HRM assays were designed and optimized for each of the coding exons of the PORCN gene, processing genomic DNA samples form a non-affected control and a patient complying with the FDH diagnostic criteria. The causal mutation was characterized by Sanger sequencing from an amplicon showing a HRM trace suggesting heterozygous variation and was validated using an amplification-refractory mutation system (ARMS) assay. RESULTS: The melting profiles suggested the presence of a variant in the patient within exon 1. Sanger sequencing revealed a previously unknown C to T transition replacing a glutamine codon for a premature stop codon at position 28, which was validated using ARMS. CONCLUSIONS: Next-generation sequencing facilitates the molecular diagnosis of monogenic disorders; however, its cost-benefit ratio is not optimal when a single, small or medium size causal gene is already identified and the clinical diagnostic presumption is strong. Under those conditions, as it is the case for FDH, HRM represents a cost- and labor-effective approach.
Subject(s)
Acyltransferases/genetics , Exons/genetics , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , Membrane Proteins/genetics , Nucleic Acid Denaturation/genetics , Amino Acid Sequence , Codon, Nonsense , Female , Focal Dermal Hypoplasia/physiopathology , Heterozygote , Humans , Infant , Mutation , Phylogeny , Polymerase Chain Reaction/methods , Sequence AlignmentABSTRACT
Goltz-Gorlin syndrome (GGS) (focal dermal hypoplasia) is a very rare developmental disorder affecting ectodermal and mesodermal structures. The syndrome is inherited in an X-linked manner, with the majority of affected individuals being female. We report the case of a 51-year-old man presenting with congenital skin lesions, syndactyly, facial and thoracic asymmetry, inguinal and laryngeal papillomas, cryptorchidism, polythelia, and dental anomalies. Molecular genetic analysis confirmed the clinically suspected diagnosis of GGS by detecting a known pathogenic mutation in the PORCN gene, c.502G>A [p.(Gly168Arg)] in the mosaic state. Histopathological examinations of skin biopsies of affected individuals typically show focal dermal hypoplasia and fat herniation; despite numerous skin biopsies, these characteristics were not found in the patient involved. Instead, we observed a notable reduction and fragmentation of the elastic fibers in the upper dermis. A systematic literature review regarding the histopathological presence or absence of dermal hypoplasia and/or information on elastic fibers revealed 240 histopathological descriptions of 173 individuals. Absence of dermal hypoplasia was found in 21 biopsies (8.8%). Information on elastic fibers was given in 47 cases (19.6%), showing decrease/absence in 31 cases and fragmentation of elastic fibers in 11 cases. Therefore, the histopathological absence of dermal hypoplasia does not exclude the diagnosis of the GGS. Decrease and fragmentation of elastic fibers may represent new histopathological clues to the diagnosis of this rare syndrome. At the same time, GGS should be included in the histopathological differential diagnoses of elastolytic disorders.
Subject(s)
Dermis/pathology , Elastic Tissue/pathology , Focal Dermal Hypoplasia/pathology , Acyltransferases , Adolescent , Adult , Aged , Biopsy , Child , Child, Preschool , DNA Mutational Analysis , Diagnosis, Differential , Female , Focal Dermal Hypoplasia/genetics , Genetic Predisposition to Disease , Humans , Infant , Male , Membrane Proteins , Middle Aged , Mutation , Phenotype , Predictive Value of Tests , Young AdultABSTRACT
Introducción: El síndrome de Goltz o hipoplasia dérmica focal es una enfermedad genética rara del grupo de las displasias ectodérmicas con un mecanismo de herencia dominante ligado al cromosoma X. Objetivo: Describir las características clínicas del síndrome de Goltz, su diagnóstico y tratamiento. Presentación del caso: Paciente femenina de 4 años de edad diagnosticada con síndrome de Goltz. Se valora en equipo multidisciplinario con las especialidades de genética, cirugía maxilofacial, estomatología, dermatología, oftalmología, ortopedia y el servicio de otorrinolaringología. Conclusiones: El síndrome de Goltz se caracteriza principalmente por afectación cutánea; anomalías oculares, dentales, faciales y esqueléticas; afectación del aparato gastrointestinal, urinario, cardiovascular y sistema nervioso central con grado variable de severidad. Su diagnóstico es clínico. La atención interdisciplinaria es fundamental para el adecuado diagnóstico y tratamiento; su pronóstico depende del grado de afectación(AU)
Introduction: Goltz syndrome also known as focal dermal hypoplasia is a rare genetic disease in the ectodermal dysplasia´s group and with a mechanism of dominant inheritance linked to the X chromosome. Objectives: To describe the clinical characteristics of the Goltz syndrome, its diagnosis and treatment. Case presentation: Case of a 4 year-old female patient diagnosed with Goltz syndrome. She was studied by a multidisciplinary team including Genetics, Maxillofacial Surgery, Stomatology, Dermatology, Ophthalmology, Orthopedics and ORL specialists. Conclusions: Goltz syndrome or focal dermal hypoplasia is mainly characterized by skin affectations; eyes, dental, skeletal, and face anomalies; gastrointestinal tract, urinary, cardiovascular and central nervous systems´ affections with varying degrees of severity. The diagnosis is clinical. A multidisciplinary approach is essential for a proper diagnosis and treatment; and prognosis depends on the grade of severity(AU)
Subject(s)
Humans , Female , Child, Preschool , Humans , Female , Child, Preschool , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia , Focal Dermal Hypoplasia , Case ReportsABSTRACT
RESUMEN Introducción: El síndrome de Goltz o hipoplasia dérmica focal es una enfermedad genética rara del grupo de las displasias ectodérmicas con un mecanismo de herencia dominante ligado al cromosoma X. Objetivo: Describir las características clínicas del síndrome de Goltz, su diagnóstico y tratamiento. Presentación del caso: Paciente femenina de 4 años de edad diagnosticada con síndrome de Goltz. Se valora en equipo multidisciplinario con las especialidades de genética, cirugía maxilofacial, estomatología, dermatología, oftalmología, ortopedia y el servicio de otorrinolaringología. Conclusiones: El síndrome de Goltz se caracteriza principalmente por afectación cutánea; anomalías oculares, dentales, faciales y esqueléticas; afectación del aparato gastrointestinal, urinario, cardiovascular y sistema nervioso central con grado variable de severidad. Su diagnóstico es clínico. La atención interdisciplinaria es fundamental para el adecuado diagnóstico y tratamiento; su pronóstico depende del grado de afectación(AU)
ABSTRACT Introduction: Goltz syndrome also known as focal dermal hypoplasia is a rare genetic disease in the ectodermal dysplasia´s group and with a mechanism of dominant inheritance linked to the X chromosome. Objectives: To describe the clinical characteristics of the Goltz syndrome, its diagnosis and treatment. Case presentation: Case of a 4 year-old female patient diagnosed with Goltz syndrome. She was studied by a multidisciplinary team including Genetics, Maxillofacial Surgery, Stomatology, Dermatology, Ophthalmology, Orthopedics and ORL specialists. Conclusions: Goltz syndrome or focal dermal hypoplasia is mainly characterized by skin affectations; eyes, dental, skeletal, and face anomalies; gastrointestinal tract, urinary, cardiovascular and central nervous systems´ affections with varying degrees of severity. The diagnosis is clinical. A multidisciplinary approach is essential for a proper diagnosis and treatment; and prognosis depends on the grade of severity(AU)
Subject(s)
Humans , Female , Child, Preschool , Focal Dermal Hypoplasia/diagnosis , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/drug therapy , Focal Dermal Hypoplasia/diagnostic imaging , Case ReportsSubject(s)
Focal Dermal Hypoplasia/diagnosis , Genetic Diseases, X-Linked/diagnosis , Mosaicism , Skin Diseases, Vascular/congenital , Acyltransferases/genetics , Adult , Biopsy , DNA Mutational Analysis , Dermoscopy , Diagnosis, Differential , Female , Focal Dermal Hypoplasia/blood , Focal Dermal Hypoplasia/genetics , Focal Dermal Hypoplasia/pathology , Frameshift Mutation , Genetic Diseases, X-Linked/genetics , Genetic Diseases, X-Linked/pathology , Humans , Membrane Proteins/genetics , Skin/diagnostic imaging , Skin/pathology , Skin Diseases, Vascular/diagnosis , Skin Diseases, Vascular/genetics , Skin Diseases, Vascular/pathologyABSTRACT
Focal dermal hypoplasia (FDH, Goltz syndrome, MIM #305600) constitutes a rare multisystem genetic disorder of the skin, skeleton, teeth and eyes with considerable variation in the clinical features. FDH is transmitted as an X-linked dominant trait and is caused by mutations in PORCN. In male children, hemizygous PORCN mutations are lethal in utero. Around 300 cases have been reported in the literature to date. About 10% of them are male patients presenting with either Klinefelter syndrome (karyotype 47, XXY) or mosaicism of a postzygotic mutation. Here we describe four cases of women with typical features of FDH, in whom a PORCN mutation was found in DNA from affected cutaneous tissue but not in DNA from peripheral blood. This study suggests that mosaicism caused by a postzygotic mutation occurs more often than assumed to date in female patients with FDH. A negative analysis performed on peripheral blood DNA does not exclude the diagnosis of FDH and it is therefore of practical importance to analyse DNA from the affected skin in order to identify low-level mosaicism and thus to improve diagnostic precision. In total, we found two missense variants, one novel indel and one novel splice-site variant. Individuals harbouring postzygotic mosaicism run a risk of transmitting the disorder to their daughters, because the maternal mosaic could also affect the gonads.
Subject(s)
Acyltransferases/genetics , Focal Dermal Hypoplasia/genetics , Membrane Proteins/genetics , Mosaicism , Adult , DNA Mutational Analysis , Female , Focal Dermal Hypoplasia/blood , Focal Dermal Hypoplasia/pathology , High-Throughput Nucleotide Sequencing , Humans , Mouth Mucosa/pathology , Skin/pathology , Young Adult , ZygoteABSTRACT
Focal dermal hypoplasia (FDH), also known as Goltz-Gorlin syndrome, is a rare, multisystemic, X-linked dominant genodermatosis characterized by defective development of mesodermal and ectodermal tissues. Major clinical features of the disorder are skin manifestations, skeletal defects, and developmental eye abnormalities. FDH is caused by heterozygous mutations in the PORCN gene located at Xp11.23, and 90% of individuals with FDH are females. Here, we report a female patient with cutaneous changes, multiple eye anomalies, short stature, and ectrodactyly of the right foot. These clinical findings were compatible with the diagnosis of FDH, and a novel mutation, NM_022825.3:c.488delG was found in the PORCN gene causing a premature stop codon.
Subject(s)
Acyltransferases/genetics , Focal Dermal Hypoplasia/genetics , Frameshift Mutation , Membrane Proteins/genetics , Adult , Female , Focal Dermal Hypoplasia/pathology , HumansABSTRACT
OBJECTIVE: Focal cortical dysplasias (FCDs) are an important cause of drug-resistant epilepsy. In this work, we aimed to investigate whether abnormal gene regulation, mediated by microRNA, could be involved in FCD type II. METHODS: We used total RNA from the brain tissue of 16 patients with FCD type II and 28 controls. MicroRNA expression was initially assessed by microarray. Quantitative polymerase chain reaction, in situ hybridization, luciferase reporter assays, and deep sequencing for genes in the mTOR pathway were performed to validate and further explore our initial study. RESULTS: hsa-let-7f (p = 0.039), hsa-miR-31 (p = 0.0078), and hsa-miR34a (p = 0.021) were downregulated in FCD type II, whereas a transcription factor involved in neuronal and glial fate specification, NEUROG2 (p < 0.05), was upregulated. We also found that the RND2 gene, a NEUROG2-target, is upregulated (p < 0.001). In vitro experiments showed that hsa-miR-34a downregulates NEUROG2 by binding to its 5'-untranslated region. Moreover, we observed strong nuclear expression of NEUROG2 in balloon cells and dysmorphic neurons and found that 28.5% of our patients presented brain somatic mutations in genes of the mTOR pathway. INTERPRETATION: Our findings suggest a new molecular mechanism, in which NEUROG2 has a pivotal and central role in the pathogenesis of FCD type II. In this way, we found that the downregulation of hsa-miR-34a leads to upregulation of NEUROG2, and consequently to overexpression of the RND2 gene. These findings indicate that a faulty coupling in neuronal differentiation and migration mechanisms may explain the presence of aberrant cells and complete dyslamination in FCD type II. Ann Neurol 2018;83:623-635.
Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Epilepsy/metabolism , Focal Dermal Hypoplasia/metabolism , Malformations of Cortical Development/metabolism , Nerve Tissue Proteins/metabolism , Adolescent , Adult , Child , Child, Preschool , Drug Resistant Epilepsy/genetics , Epilepsy/drug therapy , Epilepsy/genetics , Female , Focal Dermal Hypoplasia/genetics , Humans , Infant , Male , Neurons/metabolism , TOR Serine-Threonine Kinases/metabolism , Transcription Factors/genetics , Young Adult , rho GTP-Binding Proteins/metabolismABSTRACT
OBJECTIVE: To describe the varying phenotypic spectrum of Focal Dermal Hypoplasia (FDH) and to emphasize the need for identifying the condition in mildly affected females which is crucial for offering a prenatal diagnosis in subsequent pregnancy owing to the risk of having a severely affected baby. METHODS: The phenotype-genotype correlation of 4 patients with FDH, over a period of 11 y from the genetic clinic in a tertiary care centre from Kerala, India was done. RESULTS: All four mutation proven patients were females (2 adults and 2 children). One of the adult female subjects were mildly affected, though she had a history of having a severely affected female child who expired on day six. Among the 2 affected children, one of them had an unaffected mother and the other had an affected mother. CONCLUSIONS: FDH has a wide clinical spectrum from very subtle findings to severe manifestations. The lethality of the condition in males and the disfigurement and multisystem involvement in females highlights the importance of confirmation of diagnosis by molecular analysis so that the family can be offered prenatal diagnosis in subsequent pregnancy.