Stephen R. Braddock

Further delineation of Kabuki syndrome in 48 well-defined new individuals†

Kabuki syndrome is a multiple congenital anomaly/mental retardation syndrome. This study of Kabuki syndrome had two objectives. The first was to further describe the syndrome features. In order to do so, clinical geneticists were asked to submit cases—providing clinical photographs and completing a phenotype questionnaire for individuals in whom they felt the diagnosis of Kabuki syndrome was secure. All submitted cases were reviewed by four diagnosticians familiar with Kabuki syndrome. The diagnosis was agreed upon in 48 previously unpublished individuals. Our data on these 48 individuals show that Kabuki syndrome variably affects the development and function of many organ systems. The second objective of the study was to explore possible etiological clues found in our data and from review of the literature. We discuss advanced paternal age, cytogenetic abnormalities, and familial cases, and explore syndromes with potentially informative overlapping features. We find support for a genetic etiology, with a probable autosomal dominant mode of inheritance, and speculate that there is involvement of the interferon regulatory factor 6 (IRF6) gene pathway. Very recently, a microduplication of 8p has been described in multiple affected individuals, the proportion of individuals with the duplication is yet to be determined.

Further delineation of the phenotype associated with heterozygous mutations in ZFHX1B.

Mutations or deletions involving ZFHX1B (previously SIP1) have recently been found to cause one form of syndromic Hirschsprung disease (HSCR), associated with microcephaly, mental retardation, and distinctive facial features. Patients with the characteristic facial phenotype and severe mental retardation, but without HSCR, have now also been shown to have mutations in this gene. Mutations of ZFHX1B are frequently associated with other congenital anomalies, including congenital heart disease, hypospadias, renal tract anomalies, and agenesis of the corpus callosum (ACC). We present the clinical data and mutation analysis results from a series of 23 patients with this clinical syndrome, of whom 21 have proven ZFHX1B mutations or deletions (15 previously unpublished). Two patients with the typical features (one with and one without HSCR) did not have detectable abnormalities of ZFHX1B. We emphasize that this syndrome can be recognized by the facial phenotype in the absence of either HSCR or other congenital anomalies, and needs to be considered in the differential diagnosis of dysmorphism with severe mental retardation +/− epilepsy.

Syndrome of coronal craniosynostosis with brachydactyly and carpal/tarsal coalition due to Pro250Arg mutation in FGFR3 gene

Recently, a unique Pro250Arg point mutation in fibroblast growth factor receptor 3 (FGFR3) was reported in 61 individuals with coronal craniosynostosis from 20 unrelated families [Muenke et al. (1997): Am J Hum Genet 60:555-564]. The discovery of this apparently common mutation has resulted in the definition of a recognizable syndrome, through analysis of subtle clinical findings in families who were previously thought to have a variety of other craniosynostosis syndromes. Previous diagnoses in some of these families have included Jackson-Weiss, Saethre-Chotzen, and Pfeiffer syndromes, as well as Adelaide-type craniosynostosis and brachydactyly-craniosynostosis syndrome [Adès et al. (1994): Am J Med Genet 51:121-130; von Gernet et al. (1996): Am J Med Genet 63:177-184; Reardon et al. (1997): J Med Genet 34:632-636; Bellus et al. (1996): Nat Genet 14:174-176; Hollaway et al. (1995): Hum Mol Genet 4:681-683; Glass et al. (1994): Clin Dysmorphol 3:215-223]. There appears to be a need to further delineate the phenotype associated with this common mutation in FGFR3. We compare the clinical characteristics of previously reported cases of this unique Pro250Arg mutation with those of two additional families and suggest that this syndrome with a unique mutational basis be designated coronal craniosynostosis with brachydactyly and carpal/tarsal coalition due to Pro250Arg mutation in FGFR3 gene, to emphasize the distinctive findings which may be present even in the absence of coronal craniosynostosis.

Fetal sex and maternal asthma control in pregnancy

Asthma is a prevalent chronic disorder that might substantially complicate pregnancy. Some recent reports suggest that the presence of a female fetus might be associated with worse maternal asthma symptoms during pregnancy. We tested this hypothesis using the sample of 719 pregnant women with asthma prospectively enrolled in the OTIS study. The presence of a female fetus was associated with a higher incidence of hospitalizations for asthma during pregnancy (OR = 1.84; 95% CI: 1.05; 3.21) independent of maternal age, BMI, ethnicity, smoking, and socioeconomic status. The current study suggests that pregnant asthmatic women carrying a girl might be more susceptible to asthma exacerbations.

Weaver syndrome: Autosomal dominant inheritance of the disorder†

Weaver syndrome (WS), a condition first described in 1974 by Weaver et al., consists of macrosomia, advanced skeletal age, characteristic pattern of facial and radiographic anomalies, and contractures. Although there have been three reports of close relatives (sibs or both parent and offspring) affected with this condition, the syndrome generally occurs sporadically, and the recurrence risk in sporadic cases appears to be low. We report here on a family in which the propositus and his sister were born with the facial phenotype, club feet, and macrosomia characteristic of WS. Their father had macrosomia and macrocephaly as an adult, and childhood photos show clearly that he has WS. Two sisters of the propositus have had normal growth and development. The syndrome in this family appears to be inherited in an autosomal dominant fashion.

Linking Antley–Bixler syndrome and congenital adrenal hyperplasia: A novel case of P450 oxidoreductase deficiency†

The Antley–Bixler syndrome (ABS) is a multiple congenital malformation syndrome with craniosynostosis, radiohumeral synostosis, femoral bowing, choanal atresia or stenosis, joint contractures, urogenital abnormalities and, often, early death. Autosomal recessive and dominant inheritance have been postulated, as has fluconazole teratogenesis. Mutations in POR (P450 (cytochrome) oxidoreductase, an essential electron donor to enzymes participating in cholesterol biosynthesis), have been identified in some patients with the ABS phenotype. Recent evidence suggests that these mutations cause attenuated steroid hydroxylation, which in turn, causes congenital adrenal hyperplasia (CAH) with ambiguous genitalia in both sexes and glucocorticoid deficiency. Here, we report on a new patient with findings of both ABS and CAH that further illustrates how low maternal estriol at prenatal screening can serve as a marker steroid facilitating early diagnosis.

Anaesthetic implications of Nager syndrome

Nager acrofacial dysostosis is an oromandibular hypogenesis syndrome with associated limb abnormalities. Although it shares some phenotypic features with Treacher‐Collins syndrome, it is recognized as a separate disorder. The physical features of Nager syndrome include down slanted palpebral fissures, malar hypoplasia, a high nasal bridge, atretic external auditory canals, cleft palate and micrognathia. Preaxial limb malformations include absent or hypoplastic thumbs, hypoplasia of the radius and shortened humeral bones. Of primary concern to the anaesthetist are the midface and mandibular manifestations which may complicate perioperative airway management. These problems may also manifest in the postoperative period with airway obstruction. Associated defects have included vertebral malformations with reports of cervical spine involvement, congenital cardiac defects and upper limb defects affecting the preaxial or radial side. We describe a 7‐year‐old boy with Nager syndrome who required anaesthetic care during placement of a syringopleural shunt for drainage of a spinal cord syrinx. The perioperative implications of this disorder are reviewed.

Frontonasal malformation and the oculoauriculovertebral spectrum : The oculoauriculofrontonasal syndrome

Frontonasal malformation (FNM) is a developmental field defect representing abnormal morphogenesis of the frontonasal eminence. The oculoauriculovertebral spectrum (OAVS) has been used to describe a broader range of first and second branchial-arch defects including hemifacial microsomia and Goldenhars syndrome. A combination of FNM and OAVS has been described in the literature in 13 cases. This condition has been labeled as the oculoauriculofrontonasal syndrome, as well as ophthalmofrontonasal dysplasia. We have evaluated four patients with both FNM and OAVS. The pattern of malformation involves only the craniofacies: they have no vertebral defects, heart disease, or encephaloceles. The categorization of these four individuals and those in the literature raises interesting issues regarding syndrome classification. Originally, it was suggested that perhaps this disorder was a variation of Goldenhars syndrome. However, now that it has become evident that FNM and OAVS are malformation patterns of etiologic and presumably pathogenetic heterogeneity, a more likely hypothesis is that when these two defects occur together, this represents a unique syndrome pattern. The purpose of this article is to suggest that the combination of OAVS and FNM may be a distinct entity, representing a discreet subset of patients.

A new recessive syndrome with VATER-like defects, pulmonary hypertension, abnormal ears, blue sclera, laryngeal webs, and persistent growth deficiency.

VATER association is a term frequently used to describe children with multiple malformations. However, occasionally these children have malformations that are not typical of VATER defects and may represent unique multiple malformation syndromes with specific prognoses and recurrence risks. Two siblings with a heretofore previously undescribed multiple malformation syndrome are presented whose features include vertebral defects, cardiac abnormalities, pulmonary hypertension, laryngeal webs, blue sclerae, and persistent growth deficiency. Autosomal recessive inheritance is suggested. These cases suggest that other individuals labeled VATER association with multiple other defects should be reviewed more closely to give accurate prognosis and recurrence risk information to families.

Tertiary trisomy due to a reciprocal translocation of chromosomes 5 and 21 in a four-generation family

Tertiary trisomy, or double trisomy, is a rare occurrence. We present two individuals with a previously unreported tertiary trisomy for chromosomes 5p and 21q in an eight-generation pedigree. Their phenotypes are compared with other partial trisomies of either 5p or 21q from the literature. The propositus was diagnosed with trisomy 21 at 2 years of age after a karyotype study for short stature and developmental delay. His phenotype was described as atypical for Down syndrome. He presented at 9 years of age because of pervasive behavioral problems and obesity. He was brachycephalic with a flattened nasal bridge, but he lacked other characteristics of trisomy 21. Because of lack of phenotypic evidence of Down syndrome, a repeat karyotype was obtained and showed 47,XY, +der(21)t(5;21)(p15.1; q22.1), incorporating partial trisomies of both chromosomes 5 and 21. Mother had a balanced translocation, 46, XX,t(5;21)(p15.1; q22.1); 8 other relatives were examined. The translocation originated from the maternal great-grandmother, but only the propositus and his mentally retarded aunt had a similar phenotye and the derivative chromosome. Fluorescence in situ hybridization showed absence of band 21q22.2 in the derivative chromosome of the propositus and his aunt, indicating that neither had trisomy for the Down syndrome critical region. These cases represent a unique double partial trisomy of chromosome arms 5p and 21q that occurred because of 3:1 malsegregation of a reciprocal translocation. These cases further demonstrate that phenotypic discordance with cytogenetic results dictate further investigation using advanced cytogenetic hybridization.