Expanding the genotypic spectrum of CCBE1 mutations in Hennekam syndrome

Hennekam lymphangiectasia-lymphedema syndrome is an autosomal recessive disorder, with 25% of patients having mutations in CCBE1. We identified a family with two brothers presenting with primary lymphedema, and performed exome sequencing to determine the cause of their disease. Analysis of four family members showed that both affected brothers had the same rare compound heterozygous mutations in CCBE1. The presumed paternally inherited NM_133459.3:c.310G>A; p.(Asp104Asn), lies adjacent to other known pathogenic CCBE1 mutations, while the maternally inherited NM_133459.3:c.80T>C; p.(Leu27Pro) lies in the CCBE1 signal peptide, which has not previously been associated with disease. Functional analysis in a zebrafish model of lymphatic disease showed that both mutations lead to CCBE1 loss of function, confirming the pathogenicity of these variants and expanding the genotypic spectrum of lymphatic disorders. (c) 2016 Wiley Periodicals, Inc

Mutations in the voltage-gated potassium channel gene KCNH1 cause Temple-Baraitser syndrome and epilepsy (vol 47, pg 73, 2015)

"Mutations in the voltage-gated potassium channel gene KCNH1 cause Temple-Baraitser syndrome and epilepsy" published in Nature Genetics (2015), volume 47, pp.73-77

The oculoauriculovertebral spectrum: refining the estimate of birth prevalence

The oculoauriculovertebral spectrum (OAVS) is a well-described pattern of congenital malformations primarily characterized by hemifacial microsomia and/or auricular dysplasia. However, the birth prevalence of OAVS is poorly characterized. Figures ranging from 1 in 150,000 through to 1 in 5,600 can be found in the literature - the latter figure being the most frequently quoted. This study aims to evaluate the reasons behind such discrepant figures and to refine the estimated birth prevalence of OAVS. Published reports on the incidence and prevalence of OAVS were systematically sought after. This evidence was critically reviewed. Data from appropriate studies was amalgamated to refine the estimate of the birth prevalence for OAVS. Two main reasons were identified why birth prevalence figures for OAVS are so highly discrepant: differing methods of case ascertainment and the lack of a formal definition for OAVS. This study refines the estimate of birth prevalence for OAVS to between 1 in 40,000 and 1 in 30,000. This number needs to be confirmed in a large well-designed prospective study using a formally agreed-upon definition for OAVS

Neonatal severe hyperparathyroidism: an important clue to the aetiology

Neonatal severe hyperparathyroidism is a rare condition that presents as striking hyperparathyroidism, hypercalcaemia, and metabolic bone disease. The aetiology needs to be determined soon after diagnosis to direct appropriate management and to determine an accurate prognosis. Taking a family history is a valuable clinical tool in paediatric medicine. Presented here is the case of a neonate presenting with severe hyperparathyroidism. Obtaining the family history, coupled with basic parental studies, enabled a rapid aetiological diagnosis, which allowed for conservative management

Chacterizing the oculoauriculofrontal syndrome

Human dysmorphology syndromes are frequently defined by characteristic abnormalities in facial morphogenesis. Two such well recognized syndromes are the oculoauriculovertebral spectrum (OAVS) and frontonasal dysplasia (FND). OAVS is diagnosed on the basis of the presence of typical facial features which can include microtia, preauricular tags, hemifacial microsomia, lateral face clefting, epibulbar dermoids, and upper palpebral colobomata. FND is characterized by ocular hypertelorism, nasal clefting, and anterior cranium bifidum occultum. After the first patient was described with features of both OAVS and FND, at least a further 25 patients presenting the 'oculoauriculofrontonasal syndrome' (OAFNS) have been reported. We report on four more patients with OAFNS and review their features, together with those of the other patients reported in the medical literature. We suggest that, statistically, OAFNS is more likely to be a sporadically occurring condition rather than an inherited autosomal recessive trait, as previously suggested. We cannot, however, definitively exclude the possibility of autosomal dominant transmission. Considering the question of whether OAFNS is a part of OAVS, FND, or a distinct clinical entity, we conclude that, for the time being, OAFNS should be considered to be a distinct syndrome, to further our understanding of the aetiology of these conditions

Waiting for a diagnosis in Rubinstein–Taybi: The journey from “ignorance is bliss” to the value of “a label”

The journey to receiving a diagnosis for rare genetic disease can be long and emotionally impactful. This study describes parental experiences of receiving their child's diagnosis of Rubinstein–Taybi syndrome (RTS), a rare genetic condition characterized by growth and developmental delay together with dysmorphic features. Parents from the RTS Australia support group participated in qualitative, semi-structured phone interviews, which were transcribed verbatim and thematically analyzed. Questions focused on psychosocial challenges and benefits pre and post-diagnosis. Ten mothers and three fathers participated, with the mean age of diagnosis being 8 months. Parents reported positive psychological effects from a slight delay in diagnosis, and negative effects from an extended diagnostic delay, suggesting the ideal time for a parent to receive a diagnosis lies in the post attachment stage, prior to the development of significant parental concerns. This stage would vary depending on condition severity. Parents desired a diagnosis to reduce uncertainty; however, uncertainty remained post diagnosis, and shifted its focus from broadly encompassing etiology and prognosis, to specifically focusing on concerns regarding severity within the spectrum. Perceived benefits of a diagnosis mainly centered on the provision of a label. Parents articulated that a label increased social acceptance, enhanced coping, promoted communication, and improved access to medical, financial, and support services. This study provides insights into the experience of families prior to and following receipt of a diagnosis. It also highlights the possibility of an optimal time window to receive a diagnosis; in which bonding is maximized and parental distress is minimized