Signs Of Ectodermal Dysplasia Research Articles

Novel EDAR mutation in tooth agenesis and variable associated features

Tooth agenesis (TA) is the developmental absence of one or more permanent teeth. We report on 10 members of a Pakistani family afflicted with TA with variable associated features inherited in autosomal dominant fashion with full penetrance. The malformation is bilateral in the majority of cases, and hallmark feature is the absence of lateral and central incisors and canines whereas first and second premolars are involved less often. Affected individuals also have pronounced variable features associated with TA such as diastema between central incisors, overgrown labial frenum, peg-shaped lower incisors, delayed exfoliation, over-erupted upper incisors and malocclusion but have no other signs of ectodermal dysplasia. Through linkage analysis coupled with exome sequencing, we identified novel nonsense variant EDAR c.1302G>A, p.(Trp434*). The variant is deduced to create a premature termination codon that leads to the deletion of the 15 C-terminal residues. Heterozygous EDAR variants most commonly cause hypohydrotic ectodermal dysplasia, but recently one nonsense and 10 missense variants have been reported in nonsyndromic TA, some with few mild features of hypohydrotic ectodermal dysplasia. The phenotype in the family we present, the largest with EDAR-related TA reported to date, is highly variable and without any signs of ectodermal dysplasia.

Ангидротическая эктодермальная дисплазия у новорожденного ребенка (клиническое наблюдение)

The article describes step-by-step diagnostic approach for identifying the cause of fever in a newborn: from excluding infections and noninfectious factors provoking impaired thermoregulation to the diagnosis of a rare congenital disorder, anhidrotic ectodermal dysplasia (EDA) confirmed by genetic testing. EDA is a hereditary condition caused by mutations in the EDA gene encoding prenatal development of ectodermal derivatives. The main phenotypic signs of EDA are aplasia (hypoplasia) of sweat glands, dysplasia of skin and its appendages (hypotrichosis, nail hypoplasia etc.), and hypodontia. Hypoplasia or aplasia of the sweat glands results in impaired thermoregulation and, therefore, hyperthermia. Since hair and dental dysplasia do not manifest in newborns, EDA is commonly missed in newborns and diagnosed lately. Fever is one of the dangerous manifestations of EDA that, in tight swaddling, may result in death. Nonspecific clinical presentations of EDA in newborns require consultations with other specialists. Recognition of EDA clinical signs in newborns and infants (craniofacial dysmorphism, thin and dry skin, periorbital hyperpigmentation, reduction in body temperature after external cooling observed in the child) allows for early diagnosis and determines cooling strategy and further lifestyle. KEYWORDS: newborn, hyperthermia, anhidrotic ectodermal dysplasia, fever in newborns, differential diagnosis, causes of fever, molecular genetic testing. FOR CITATION: Akhmina N.I., Nikopol’skaya A.V., Bragina E.M. et al. Anhidrotic ectodermal dysplasia in a newborn: case history. Russian Journal of Woman and Child Health. 2020;3(4):340–343. DOI: 10.32364/2618-8430-2020-3-4-340-343.

Autopsy findings of ectodermal dysplasia and sex development disorder in a fetus with 19q12q13 microdeletion

A 5,6 Mb de novo 19q12-q13.12 interstitial deletion was diagnosed prenatally by array-comparative genomic hybridization in a 26 weeks male fetus presenting with intra-uterine growth retardation, left clubfoot, atypical genitalia and dysmorphic features. Autopsic examination following termination of pregnancy identified a severe disorder of sex development (DSD) including hypospadias, micropenis, bifid scrotum and right cryptorchidism associated with signs of ectodermal dysplasia: scalp hypopigmentation, thick and frizzy hair, absence of eyelashes, poorly developed nails and a thin skin with prominent superficial veins. Other findings were abnormal lung lobation and facial dysmorphism.This new case of DSD with a 19q12q13 deletion expands the phenotypic spectrum associated with this chromosomal rearrangment and suggests that WTIP is a strong candidate gene involved in male sex differentiation.

Cystinuria in a patient with 19q12q13.1 deletion.

Cystinuria is a genetic cause of kidney stones with a prevalence of 1 in 7000 births. So far, two genes have been described responsible for this disorder (SLC3A1 and SLC7A9). We report a patient with an SLC7A9 gene mutation located in 19q13.1 on one allele and with a 19q12q13 region deletion on the other allele. The characteristic clinical features of the 19q13.1 microdeletion syndrome include facial dysmorphism, signs of ectodermal dysplasia, growth retardation, neurologic features and genitourinary anomalies. Cystinuria has not yet been described as part of this syndrome, although one of its responsible genes (SLC7A9) is in the same genomic location. The index case is a 6-year-old male presented with distinctive facial features, cutis aplasia of the scalp, rudimentary teeth, microcephaly, intrauterine and postnatal growth retardation, psychomotor developmental delay, speech delay, epilepsy, inguinal hernias and cystinuria. An array-CGH analysis was performed, finding a large deletion of the 19q12q13.11 cytobands, which affects 19 genes. Two of them are involved in the 19q13.11 deletion syndrome and another affected gene is SLC7A9, responsible for type B cystinuria. Sanger sequencing was performed as well, detecting a heterozygous mutation of the SLC7A9 gene, located in 19q13.1. As far as we know, this is the first described case of cystinuria in a patient with SLC7A9 gene mutation located in 19q13.1 on one allele and with 19q12q13 region deletion on the other allele. Although this patient can be classified as a type B heterozygote and, therefore, his renal prognosis is not severe, the occasional nephrolithiasis found in such patients justifies a close follow-up with regular testing of urinary cystine excretion. We suggest that the recessive behavior of this case, explains the clinical features regarding cystinuria. We propose that in the face of patients affected of a phenotype matchable with 19q13.11 syndrome and cystinuria, a mutational or sequencing study of the SLC7A9 gene should be performed to allow an early onset of diagnosis and treatment.

Cutis Aplasia as a clinical hallmark for the syndrome associated with 19q13.11 deletion: the possible role for UBA2 gene.

BackgroundWide genome screening through array comparative genomic hybridization made possible the recognition of the novel 19q13.11 deletion syndrome. There are very few cases reported with this deletion, but clinically this condition seems to be recognizable by pre and postnatal growth retardation, microcephaly, developmental delay/intellectual disabilities, speech disturbance, hypospadias (in males) and signs of ectodermal dysplasia and cutis aplasia over the posterior occiput.ResultsUsing oligoarray CGH, a 4.6 Mb deletion in 19q13.11q13.12 was detected in a 23 year old female patient that presented clinical features previously associated with 19q13.11 deletion.ConclusionsOur work reinforces the idea that a region encompassing four zinc finger genes is likely to be responsible for the syndrome, and that the difference in minor clinical manifestation depends on the genes present outside the minimal overlapping region proposed for this syndrome. We also review all cases described in the literature and discuss the correlation between haploinsufficiency of UBA2 gene and cutis aplasia present in the majority of the patients reported, and its importance as a clinical hallmark of 19q13.11 deletion syndrome, when associated with more common features like developmental delay, microcephaly, speech disturbance and hypospadias in males.

Involvement of the ocular system in hypohidrotic ectodermal dysplasia

X-linked hypohidrotic ectodermal dyplasia (XLHED) is the most common form of ectodermal dysplasia. It often presents with ocular symptoms, already in early childhood. Multiple ophthalmological tests are available, but in early childhood only tests of lower invasiveness can be applied. We have evaluated tear film tests and ocular surface staining as screening methods in pediatric patients with signs of ectodermal dysplasia. These tests may also be used in adults with confirmed XLHED to determine the severity of ocular surface disease. Twelve children and 14 adults with XLHED were subjected to a panel of tests including the ocular surface disease index (OSDI), non-invasive measurement of tear film break-up time (NIBUT), osmolarity, Schirmer test, lissamine green staining, fluorescein staining, meibography and infrared thermography. Sensitivity and specificity were determined for single tests and selected test combinations. For adults with XLHED, OSDI, NIBUT and osmolarity were the best single routine tests (sensitivity between 84.6% and 85.7%; specificity of 100%). Their combination increased the sensitivity to 92.8%. Meibography yielded optimal results (100% sensitivity and specificity). Infrared thermography revealed a typical pattern for XLHED. In children with XLHED, NIBUT or OSDI were the most convincing single tests (sensitivity of 90.9% and 83.3%, respectively; specificity of 100% each), combination of which increased the sensitivity to 100%. More invasive tests such as meibography and infrared thermography led to good results if they were tolerated. Tear film tests can help to establish an early diagnosis in individuals with suspected XLHED, even before genetic test results are available. Meibomian gland disorder and resulting hyperevaporative dry eye are typical features of XLHED. Once the diagnosis is made, tear film tests are an important instrument to establish an effective therapy of dry eye disease.

19q13.11 cryptic deletion: description of two new cases and indication for a role of WTIP haploinsufficiency in hypospadias

Developmental delay/intellectual disabilities, speech disturbance, pre- and postnatal growth retardation, microcephaly, signs of ectodermal dysplasia, and genital malformations in males (hypospadias) represent the phenotypic core of the recent emerging 19q13.11 deletion syndrome. Using array-CGH for genome-wide screening we detected an interstitial deletion of chromosome band 19q13.11 in two patients exhibiting the recognizable pattern of malformations as described in other instances of this submicroscopic genomic imbalance. The deletion detected in our patients has been compared with previously reported cases leading to the refinement of the minimal overlapping region (MOR) for this microdeletion syndrome to 324 kb. This region encompasses five genes: four zinc finger (ZNF) genes belonging to the KRAB-ZNF subfamily (ZNF302, ZNF181, ZNF599, and ZNF30) and LOC400685. On the basis of our male patient 1 and on further six male cases of the literature, we also highlighted that larger 19q13.11 deletions including the Wilms tumor interacting protein (WTIP) gene, proximal to the MOR, results in hypospadias making this gene a possible candidate for this genital abnormality due to its well-known interaction with WT1. Although the mechanism underlying the phenotypic effects of copy number alterations involving KRAB-ZNF genes at 19q13.11 has not clearly been established, we suggest their haploinsufficiency as the most likely candidate for the phenotypic core of the 19q13.11 deletion syndrome. In addition, we hypothesized WTIP gene haploinsufficiency as responsible for hypospadias.

Ectodermal dysplasia, primary hypothyroidism, and agenesis of the corpus callosum: variable expression of a single syndrome?

We present two unrelated children, a male and a female, with signs of ectodermal dysplasia, mental retardation, agenesis/ dysgenesis of the corpus callosum, and primary hypothyroidism. Reports of ectodermal dysplasia...

Genetic mapping of anhidrotic ectodermal dysplasia: DXS159, a closely linked proximal marker

Three families with anhidrotic ectodermal dysplasia (AED) have been studied by linkage analysis with seven polymorphic DNA markers from the Xp11-q21 region. Previously reported linkage to DXYS1 (Xq13-q21) has been confirmed (z (theta) = 4.08 at theta = 0.05) and we have also established linkage to another polymorphic locus, DXS159, located in Xq11-q12 (z (theta) = 4.28 at theta = 0.05). Physical mapping places DSX159 proximal to the Xq12 breakpoint of an X autosome translocation found in a female with clinical signs of ectodermal dysplasia. Of all markers that have been used in linkage analysis of AED, DXS159 would appear the closest on the proximal side of the disease locus.