Hypohidrotic ectodermal dysplasia (HED), a congenital disorder of teeth, hair, and eccrine sweat glands, is usually inherited as an X-linked recessive trait, although rarer autosomal dominant and recessive forms exist. We have studied males from four families with HED and immunodeficiency (HED-ID), in which the disorder segregates as an X-linked recessive trait. Affected males manifest dysgammaglobulinemia and, despite therapy, have significant morbidity and mortality from recurrent infections. Recently, mutations in IKK-gamma (NEMO) have been shown to cause familial incontinentia pigmenti (IP). Unlike HED-ID, IP affects females and, with few exceptions, causes male prenatal lethality. IKK-gamma is required for the activation of the transcription factor known as "nuclear factor kappa B" and plays an important role in T and B cell function. We hypothesize that "milder" mutations at this locus may cause HED-ID. In all four families, sequence analysis reveals exon 10 mutations affecting the carboxy-terminal end of the IKK-gamma protein, a domain believed to connect the IKK signalsome complex to upstream activators. The findings define a new X-linked recessive immunodeficiency syndrome, distinct from other types of HED and immunodeficiency syndromes. The data provide further evidence that the development of ectodermal appendages is mediated through a tumor necrosis factor/tumor necrosis factor receptor-like signaling pathway, with the IKK signalsome complex playing a significant role.

In 1964, Smith et al described a syndrome of microcephaly, growth and mental retardation, unusual facial appearance, syndactyly of toes 2 and 3, and genital abnormalities. Major structural malformations and early death have been uncommon in the many subsequent literature reports. We report on 19 infants with a phenotype we propose to call Smith-Lemli-Opitz syndrome (SLOS)-Type II, in which major structural abnormalities, male pseudohermaphroditism, and early lethality are common. Of these 19 patients, 18 had postaxial hexadactyly, 16 had congenital heart defect, 13 had cleft palate, and 10 had cataracts. Unusual findings seen in these patients at autopsy included Hirschsprung "disease" in five patients, unilobated lungs in six, large adrenals in four, and pancreatic islet cell hyperplasia in three. Comparison of our cases to 19 similar literature cases suggests the existence of a distinct phenotype that may be separate from SLOS as originally described. It is also inherited as an autosomal recessive, as documented by occurrence in one pair of sibs in this study and recurrence in three reported families.

SummaryBackgroundDeafness, onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS) syndrome is a rare autosomal recessive disorder of unknown cause. We aimed to identify the genetic basis of this syndrome by sequencing most coding exons in affected individuals.MethodsThrough a search of available case studies and communication with collaborators, we identified families that included at least one individual with at least three of the five main features of the DOORS syndrome: deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. Participants were recruited from 26 centres in 17 countries. Families described in this study were enrolled between Dec 1, 2010, and March 1, 2013. Collaborating physicians enrolling participants obtained clinical information and DNA samples from the affected child and both parents if possible. We did whole-exome sequencing in affected individuals as they were enrolled, until we identified a candidate gene, and Sanger sequencing to confirm mutations. We did expression studies in human fibroblasts from one individual by real-time PCR and western blot analysis, and in mouse tissues by immunohistochemistry and real-time PCR.Findings26 families were included in the study. We did exome sequencing in the first 17 enrolled families; we screened for TBC1D24 by Sanger sequencing in subsequent families. We identified TBC1D24 mutations in 11 individuals from nine families (by exome sequencing in seven families, and Sanger sequencing in two families). 18 families had individuals with all five main features of DOORS syndrome, and TBC1D24 mutations were identified in half of these families. The seizure types in individuals with TBC1D24 mutations included generalised tonic-clonic, complex partial, focal clonic, and infantile spasms. Of the 18 individuals with DOORS syndrome from 17 families without TBC1D24 mutations, eight did not have seizures and three did not have deafness. In expression studies, some mutations abrogated TBC1D24 mRNA stability. We also detected Tbc1d24 expression in mouse phalangeal chondrocytes and calvaria, which suggests a role of TBC1D24 in skeletogenesis.InterpretationOur findings suggest that mutations in TBC1D24 seem to be an important cause of DOORS syndrome and can cause diverse phenotypes. Thus, individuals with DOORS syndrome without deafness and seizures but with the other features should still be screened for TBC1D24 mutations. More information is needed to understand the cellular roles of TBC1D24 and identify the genes responsible for DOORS phenotypes in individuals who do not have a mutation in TBC1D24.FundingUS National Institutes of Health, the CIHR (Canada), the NIHR (UK), the Wellcome Trust, the Henry Smith Charity, and Action Medical Research.

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Beare-Stevenson cutis gyrata syndrome (MIM 123790) is an autosomal dominant condition characterized by the furrowed skin disorder of cutis gyrata, acanthosis nigricans, craniosynostosis, craniofacial dysmorphism, digital anomalies, umbilical and anogenital abnormalities and early death. Many of these features are characteristic of some of the autosomal dominant craniosynostotic syndromes. Mutations in Crouzon, Jackson-Weiss, Pfeiffer and Apert syndromes have been reported in the FGFR2 extracellular domain. In Crouzon syndrome patients with acanthosis nigricans, a recurrent mutation occurs in the transmembrane domain of FGFR3. We now describe the detection of FGFR2 mutations in the Beare-Stevenson cutis gyrata syndrome. In three sporatic cases, a novel missense mutation was found causing an amino acid to be replaced by a cysteine; two had the identical Ty375Cys mutation in the transmembrane domain and one had a Ser372Cys mutation in the carboxyl-terminal end of the linker region between the immunoglobulin III-like (Iglll) and transmembrane domains. In two patients, neither of these mutations were found suggesting further genetic heterogeneity.

Holoprosencephaly (HPE) is the most commonly occurring congenital structural forebrain anomaly in humans. HPE is associated with mental retardation and craniofacial malformations. The genetic causes of HPE have recently begun to be identified, and we have previously shown that HPE can be caused by haploinsufficiency for SONIC HEDGEHOG ( SHH). We hypothesize that mutations in genes encoding other components of the SHH signaling pathway could also be associated with HPE. PATCHED-1 (PTCH), the receptor for SHH, normally acts to repress SHH signaling. This repression is relieved when SHH binds to PTCH. We analyzed PTCH as a candidate gene for HPE. Four different mutations in PTCHwere detected in five unrelated affected individuals. We predict that by enhancing the repressive activity of PTCH on the SHH pathway, these mutations cause decreased SHH signaling, and HPE results. The mutations could affect the ability of PTCH to bind SHH or perturb the intracellular interactions of PTCH with other proteins involved in SHH signaling. These findings further demonstrate the genetic heterogeneity associated with HPE, as well as showing that mutations in different components of a single signaling pathway can result in the same clinical condition.

Maternal diabetes is known to have teratogenic effects. Malformations including neural tube defects, caudal dysgenesis, vertebral defects, congenital heart defects, femoral hypoplasia, and renal anomalies are described in infants of diabetic mothers. However, craniofacial anomalies have rarely been reported in such infants. Here we document craniofacial anomalies of patients born to diabetic mothers. We describe two patient populations: individuals evaluated through our genetics services for multiple malformations and individuals identified through a database search in our craniofacial clinic. The first group consists of 14 individuals evaluated in our genetics clinics who were born to diabetic mothers and had craniofacial anomalies. The second group consists of seven individuals who were identified from a craniofacial database search of patients with hemifacial microsomia and who were born to diabetic mothers. Thus, both groups were born to diabetic mothers and had hemifacial microsomia (67%), microtia (52%), hearing loss (43%), epibulbar dermoids (24%), and fused cervical vertebrae (24%). Therefore, the teratogenic effects of maternal diabetes probably include such craniofacial malformations as the oculoauriculovertebral/Goldenhar complex. Infants of diabetic mothers should be evaluated for craniofacial anomalies. Conversely, mothers of infants with craniofacial anomalies should be evaluated for diabetes to aid in counseling concerning cause and recurrence risks.

Congenital diaphragmatic defects (CDDs) may occur in malformation syndromes of varied causes. Syndromic cases of CDDs due to chromosomal defects, autosomal recessive, autosomal dominant, or X-linked inheritance have been described. In order to determine the frequency and nature of syndromes, malformations, and chromosome abnormalities associated with CDDs, we reviewed the records of all patients with CDDs evaluated over a 4-year period. During the 4-year interval, a total of 60 patients was evaluated. Of these, 29 had a therapeutic or spontaneous abortion, and 31 received postnatal care. On prenatal ultrasonography, 20 of 60 (33%) of patients with CDDs had additional anomalies. Additional anomalies, besides CDDs, were present in 15 of 31 (48%) of liveborn patients on newborn evaluation. In total, 16 patients with multiple anomalies were evaluated. Of these, 12 of 16 (75%) had additional abnormalities detected by prenatal ultrasonography. The 4 of 16 (25%) without additional anomalies on prenatal sonography had multiple anomalies found neonatally, lethal multiple pterygium syndrome being diagnosed in one case. Prenatal chromosome analysis was performed in 7 of 16 patients, and all had postnatal karyotypes. All initial karyotypes were normal. Tetrasomy 12p was documented on postnatal fibroblast analysis in one case who had percutaneous umbilical blood sampling (PUBS). Syndromes diagnosed postnatally in 7 of 16 patients (44%) include: Fryns syndrome (2), Simpson-Golabi-Behmel syndrome (2), tetrasomy 12p (1), Brachmann-de Lange syndrome (1), and lethal multiple pterygium syndrome (1). We were unable to make a specific diagnosis in 9 of 16 patients (56%) with multiple malformations. In patients with CDDs, a normal prenatal karyotype, especially if obtained by PUBS, and absence of other detected abnormalities by fetal ultrasonography, do not exclude the presence of other major anomalies, including chromosome abnormalities and severe multiple malformation syndromes.