[Focal dermal hypoplasia associated with pathogenic PORCN gene variant in postzygotic, unilateral mosaic form]. / Fokale dermale Hypoplasie durch pathogene Variante im PORCN-Gen in postzygotischer, unilateraler Mosaik-Konstellation.

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.

Cutaneous, Cranial, and Skeletal Defects in Children and Adults with Focal Dermal Hypoplasia.

BACKGROUND: The diagnostic process for children and adults manifesting a constellation of ectodermal abnormalities requires a conscientious and highly structured process. MATERIAL AND METHODS: Six girls (aged 6-month-8 years) and two older girls (aged 13 and 16 years) were born with variable skin lesions of varying intensities associated with noticeable cranial and skeletal malformation complexes. Cleft palate, abnormal dentition, and multiple papillomas were evident around the mouth, mostly bilateral but asymmetrical in the upper and lower limbs. Exaggerated frontal bossing (macrocephaly) and in some patients' microcephaly with variable skeletal defects of the craniocervical junction and diverse forms of lower limb deformities of syndactyly, polydactyly, and split-hand/foot (ectrodactyly). RESULTS: All patients manifested the constellation of abnormalities with variable intensities ranging between alopecia, papillomas, striated skin pigmentations split-hand/foot (ectrodactyly), and major bone defects. A 3D reconstruction CT scan was directed mainly to further scrutinize children with pseudo cleft lip, submucus cleft, and cleft palate. Interstingly, they manifested massive demineralization of the cranium associated with severely defective dentition. A spine 3D reconstruction CT scan in two girls showed marked cystic cavitation of the upper jaw associated with excessive cavitation of the mastoid, causing tremendous frailty of the mastoid bone. A 3D sagittal CT scan showed odontoid hypoplasia and C1-2 instability associated with the rudimentary atlas and the persistence of extensive synchondrosis of the cervico-thoracic spine. The overall clinical and radiological phenotypic characterizations were consistent with the diagnosis of focal dermal hypoplasia (Goltz syndrome). Two children manifested heterozygous mutations in the PORCN gene, chromosome Xp11. CONCLUSIONS: In this study, we believe it's a good opportunity to share our novel scientific findings, which are intriguing and can be inspiring to readers, and to further aid the current scientific literature with exceptionally new unveiling results. This is the first comprehensive study of the cranio-skeletal malformation complex in children with GS.

Case Report: Papillary thyroid carcinoma in Goltz-Gorlin syndrome.

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.

Focal Dermal Hypoplasia: Case Series.

Background: Focal dermal hypoplasia (Goltz syndrome) is a genetic multisystem disorder characterized primarily by involvement of the skin associated to face, skeletal, and eyes anomalies. The objective of the present series is to shed light on this rare syndrome and these atypical manifestations. Methodology: Our study reports the case of five Moroccan patients who present typical clinical picture of the Goltz syndrome with some rare manifestations. Results: A total of 5 patients with Goltz syndrome were evaluated. All of them are female with one familial case. The age ranged from 8 months to 35 years. A characteristic Blaschkoid hypo- and hyper-pigmented skin lesions, congenital nodular fat herniation, and skin atrophy were present in all patients. Ocular manifestations were present in 80% of patients. Cranio-facial deformity was seen in 80% of patients. Short stature and intellectual delay were documented in 80% and 40% of patients, respectively. Limb abnormality was found in all patients. Two patients had a cleft lip, one of which unusual lateral facial cleft. Limitations: Genetic testing could not be performed in the present series. Conclusions: Through this work we will discuss the different clinical signs and genetic aspects of Goltz syndrome and the interest of a good clinical expertise.

Focal Dermal Hypoplasia Associated With Lymphedema: A Case Report From Saudi Arabia.

Focal dermal hypoplasia (FDH), also known as Goltz syndrome, is a rare syndrome described in the literature. Patchy skin hypoplasia is the most evident sign. Hyperpigmentation, hypopigmentation, papillomas, limb defects, and orofacial manifestations have also been reported. A 12-year-old Saudi girl with unremarkable family history presented with FDH. The diagnosis was confirmed using a genetic study. Physical examination revealed asymmetrical streaks of vermiculate dermal atrophy, telangiectasia with hyperpigmentation, and hypopigmentation on the left half of the face, trunk, and bilateral extremities. It appears along Blashko lines. No mental impairment was observed. Intraoral examination generalized plaque-induced gingivitis with erythematous gingival hyperplasia. Examination of the teeth showed generalized enamel hypoplasia with abnormal tooth formations, malalignment, microdontia, spacing and tilting, and minimal caries. As reported cases of FDH are rare worldwide, this syndrome is yet to be fully understood. As the manifestation of the syndrome varies among cases, the management of each case is unique. This emphasizes the importance of reporting cases of FDH.

Urogenital presentation of a male patient with focal dermal hypoplasia.

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.

Progression and flaring of focal dermal hypoplasia during an acute illness.

Focal dermal hypoplasia (FDH), or Goltz syndrome, is a rare genodermatosis affecting tissues of mesodermal and ectodermal origin. The characteristic skin changes have been reported to symptomatically flare in response to certain triggers as well as to progress over time in some cases. We present the case of a 5-year-old girl with cutaneous flaring and progression of FDH in the setting of septic shock. This case adds to the growing body of literature on both flaring and progression of the cutaneous manifestations of FDH.

Porcn is essential for growth and invagination of the mammalian optic cup.

Microphthalmia, anophthalmia, and coloboma (MAC) are congenital ocular malformations causing 25% of childhood blindness. The X-linked disorder Focal Dermal Hypoplasia (FDH) is frequently associated with MAC and results from mutations in Porcn, a membrane bound O-acyl transferase required for palmitoylation of Wnts to activate multiple Wnt-dependent pathways. Wnt/ß-catenin signaling is suppressed in the anterior neural plate for initiation of eye formation and is subsequently required during differentiation of the retinal pigment epithelium (RPE). Non-canonical Wnts are critical for early eye formation in frog and zebrafish. However, it is unclear whether this also applies to mammals. We performed ubiquitous conditional inactivation of Porcn in mouse around the eye field stage. In Porcn CKO , optic vesicles (OV) arrest in growth and fail to form an optic cup. Ventral proliferation is significantly decreased in the mutant OV, with a concomitant increase in apoptotic cell death. While pan-ocular transcription factors such as PAX6, SIX3, LHX2, and PAX2 are present, indicative of maintenance of OV identity, regional expression of VSX2, MITF, OTX2, and NR2F2 is downregulated. Failure of RPE differentiation in Porcn CKO is consistent with downregulation of the Wnt/ß-catenin effector LEF1, starting around 2.5 days after inactivation. This suggests that Porcn inactivation affects signaling later than a potential requirement for Wnts to promote eye field formation. Altogether, our data shows a novel requirement for Porcn in regulating growth and morphogenesis of the OV, likely by controlling proliferation and survival. In FDH patients with ocular manifestations, growth deficiency during early ocular morphogenesis may be the underlying cause for microphthalmia.

Focal Dermal Hypoplasia with Osteopathia Striata.

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.

Focal Dermal Hypoplasia (Goltz Syndrome): A Case Report Showing a Wide Variety of Systemic and Oral Manifestations.

Focal dermal hypoplasia (FDH), also known as Goltz syndrome, consists of an unusual genodermatosis that affects tissues of ectodermal and mesodermal origin and various organs and systems, especially skin, bones, eyes, and oral cavity. While systemic manifestations of FDH have been well documented, the oral manifestations have not been extensively discussed. We present a 22-year-old female patient with history of FDH that showed a variety of systemic and oral manifestations. FDH was diagnosed at birth based on cutaneous alterations. Extra and intraoral examination showed facial asymmetry, lip and perioral atrophy, upper lip papilloma, malocclusion, enamel hypoplasia, and gingival hyperplasia. Mucosal lesions, periodontal diseases, and malocclusion were treated by oral surgery, periodontal therapy and orthodontic treatment, respectively. Although FDH is an uncommon syndrome, health professionals should be aware of its systemic and oral manifestations to establish an early diagnosis and adequate treatment.

Novel insights into PORCN mutations, associated phenotypes and pathophysiological aspects.

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.

Novel uses of laser therapy in Goltz syndrome.

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.

Two new patients with focal dermal hypoplasia: A novel PORCN variant and insights on the diagnostic considerations.

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.

Structural model of human PORCN illuminates disease-associated variants and drug-binding sites.

Wnt signaling is essential for normal development and is a therapeutic target in cancer. The enzyme PORCN, or porcupine, is a membrane-bound O-acyltransferase (MBOAT) that is required for the post-translational modification of all Wnts, adding an essential mono-unsaturated palmitoleic acid to a serine on the tip of Wnt hairpin 2. Inherited mutations in PORCN cause focal dermal hypoplasia, and therapeutic inhibition of PORCN slows the growth of Wnt-dependent cancers. Based on homology to mammalian MBOAT proteins, we developed and validated a structural model of human PORCN. The model accommodates palmitoleoyl-CoA and Wnt hairpin 2 in two tunnels in the conserved catalytic core, shedding light on the catalytic mechanism. The model predicts how previously uncharacterized human variants of uncertain significance can alter PORCN function. Drugs including ETC-159, IWP-L6 and LGK-974 dock in the PORCN catalytic site, providing insights into PORCN pharmacologic inhibition. This structural model enhances our mechanistic understanding of PORCN substrate recognition and catalysis, as well as the inhibition of its enzymatic activity, and can facilitate the development of improved inhibitors and the understanding of disease-relevant PORCN mutants. This article has an associated First Person interview with the joint first authors of the paper.

De Novo PORCN and ZIC2 Mutations in a Highly Consanguineous Family.

We present a Turkish family with two cousins (OC15 and OC15b) affected with syndromic developmental delay, microcephaly, and trigonocephaly but with some phenotypic traits distinct between them. OC15 showed asymmetrical skeletal defects and syndactyly, while OC15b presented with a more severe microcephaly and semilobal holoprosencephaly. All four progenitors were related and OC15 parents were consanguineous. Whole Exome Sequencing (WES) analysis was performed on patient OC15 as a singleton and on the OC15b trio. Selected variants were validated by Sanger sequencing. We did not identify any shared variant that could be associated with the disease. Instead, each patient presented a de novo heterozygous variant in a different gene. OC15 carried a nonsense mutation (p.Arg95*) in PORCN, which is a gene responsible for Goltz-Gorlin syndrome, while OC15b carried an indel mutation in ZIC2 leading to the substitution of three residues by a proline (p.His404_Ser406delinsPro). Autosomal dominant mutations in ZIC2 have been associated with holoprosencephaly 5. Both variants are absent in the general population and are predicted to be pathogenic. These two de novo heterozygous variants identified in the two patients seem to explain the major phenotypic alterations of each particular case, instead of a homozygous variant that would be expected by the underlying consanguinity.

A de novo mutation in the PORCN gene in a newborn with Goltz syndrome / 中华皮肤科杂志

Objective:To report a newborn with Goltz syndrome and a de novo mutation in the PORCN gene. Methods:Clinical data collected from a newborn with Goltz syndrome were retrospectively analyzed. Peripheral venous blood samples were obtained from the newborn and her parents, genomic DNA was extracted, whole-exome sequencing was performed to screen disease-causing genes in the patient, and Sanger sequencing was conducted to verify the mutant genes.Results:The 7-hour-old female newborn presented with scalp defects, multiple epidermal defects on the face and inner side of both knee joints, deformity of the left auricle, syndactyly of the middle and ring fingers of the right hand as well as the great and second toes of the right foot, and lobster-claw deformity of the left foot. Genetic testing showed that a fragment TCCTTCCA was inserted at position 514-521 in exon 4 of the PORCN gene of the patient (c.514_521dupTCCTTCCA) , resulting in the substitution of serine by proline at amino acid position 175 (p.S175Pfs*14) , followed by translation termination at the 14th codon. This heterozygous mutation was not found in her parents. The patient was diagnosed with Goltz syndrome. Conclusions:There are various phenotypes of Goltz syndrome, and a confirmed diagnosis of Goltz syndrome can be made based on PORCN gene mutations and clinical manifestations. The heterozygous mutation c.514_521dupTCCTTCCA is a novel mutation.

Implementation of high-resolution melting analysis of the porcupine (PORCN) gene for molecular diagnosis of focal dermal hypoplasia: Identification of a novel mutation.

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.