[Focal dermal hypoplasia associated with pathogenic PORCN gene variant in postzygotic, unilateral mosaic form]

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.

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.

Prenatal diagnosis of PORCN-related developmental syndrome in a fetus: A novel phenotype

We report a case of a female fetus born to an unrelated couple with a complex fetal phenotype of a pleural effusion, a cardiac malformation, and syndactyly of the toes. Prenatal exome sequencing identified a variant of uncertain significance in the PORCN gene that was upgraded to likely pathogenic following postnatal clinical examination. The phenotype described in cases with variants in the PORCN gene is often associated with findings that cannot be prospectively diagnosed by ultrasonography. This is the first report of a prenatal phenotype involving a fetal effusion associated with variants in the PORCN gene, with skeletal findings identified later in gestation on ultrasonography. The diagnosis was confirmed on neonatal examination.

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. This article is protected by copyright. All rights reserved.

Non-syndromic anophthalmia/microphthalmia can be caused by a PORCN variant inherited in X-linked recessive manner

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.

The Rare Neurocutaneous Disorders: Update on Clinical, Molecular, and Neuroimaging Features

Phakomatoses, also known as neurocutaneous disorders, comprise a vast number of entities that predominantly affect structures originated from the ectoderm such as the central nervous system and the skin, but also the mesoderm, particularly the vascular system. Extensive literature exists about the most common phakomatoses, namely neurofibromatosis, tuberous sclerosis, von Hippel-Lindau and Sturge-Weber syndrome. However, recent developments in the understanding of the molecular underpinnings of less common phakomatoses have sparked interest in these disorders. In this article, we review the clinical features, current pathogenesis, and modern neuroimaging findings of melanophakomatoses, vascular phakomatoses, and other rare neurocutaneous syndromes that may also include tissue overgrowth or neoplastic predisposition.

Unilateral Focal Dermal Hypoplasia (Goltz Syndrome): Case Report and Literature Review

Focal dermal hypoplasia (FDH) or Goltz syndrome is a rare X-linked dominant multisystemic disease involving the ectoderm, mesoderm, and endoderm. About 95% of the cases appear de novo, and 90% of them are females. Recently, the studies revealed that FDH is caused by a mutation in the PORCN gene. We report a case of unilateral FDH or Goltz syndrome in a 16-year-old girl presenting with hypopigmented-reticulated atrophic macules and patches in a linear pattern distributed along the lines of Blaschko over the right side of the face and the right arm. Also she is having hypoplasia of the right breast with dental enamel abnormality and partial anodontia in the lower jaw. Sparse hair and partial alopecia on the right side (scalp, eyebrows, and eyelashes) were also observed.

Laser-Induced Neocollagenesis in Focal Dermal Hypoplasia Associated With Goltz Syndrome in a Girl

Importance

Current models of Goltz syndrome cannot estimate the overall neocollagenesis and marked shift in collagen types after ablative fractional laser resurfacing (AFR) within treated areas of focal dermal hypoplasia (FDH).

Objectives

To clinically improve FDH by using AFR to characterize the specific ratio of collagen types associated with observed clinical changes.

Design, Setting, and Participants

This case report of a girl with Goltz syndrome used extensive laboratory evaluation and multiple observers blinded to the patient's clinical status. Serial samples of clinically unaffected skin constituted internal control specimens, with clinical and histologic evaluations performed as part of a multicenter investigation. The analysis tested the hypothesis that thermal microtrauma caused by AFR created a unique environment that activated latent genes, inducing neocollagenesis and allowing the patient to adaptively produce the collagen subtype that was specifically deficient at baseline.

Interventions

Two AFR treatments were administered within an area of FDH. Histologic comparison of the pretreatment and posttreatment skin was performed using serial internal controls.

Main Outcomes and Measures

Histologic changes, including Herovici collagen staining to differentiate between types I and III collagen, within a treated area of mosaically affected FDH compared with clinically unaffected skin.

Results

This female patient presented in the second decade of life with self-described red, itchy skin within a large plaque of FDH on her left posterior thigh and calf. After AFR, skin tightening and symptomatic relief were reported. Histologic findings demonstrated objective thickening of the dermal collagen. A marked shift in collagen predominance from type III (fetal/early wound) to type I (adult/mature) was observed.

Conclusions and Relevance

Although further study is needed, this report shows promising results and raises important questions about gene expression and the epigenetics of Goltz syndrome-associated mutations and the local effects of AFR. Coupled with more rigorous investigation, this novel technique may help reveal molecular workarounds permitting innovative therapies that take advantage of the subtly different collagens that exist within the skin.