Platelet dysfunction in a patient with the Opitz (BBBG) syndrome

An 11-year-old girl with Opitz (BBBG) syndrome presented with a bleeding disorder. Studies showed an immune-mediated qualitative platelet dysfunction in the absence of thrombocytopenia. This is the first report of hemostatic dysfunction in a patient with the Opitz (BBBG) syndrome. This report considers the possible relationship of the platelet dysfunction to the Opitz (BBBG) syndrome and its treatment. © 1992 Wiley-Liss, Inc.     

BBBG syndrome or Opitz syndrome: new family

We report on a family where the propositus had G syndrome, including laryngeal cleft, and another relative had the facial anomalies typical of the BBB syndrome. We review the literature on the BBB and G syndrome, and argue that no clinical or laboratory criteria permit a differential diagnosis of the two syndromes. Therefore, we suggest that they should be considered variable expression of the same gene. The name BBBG syndrome is proposed for the amalgamated syndrome.     

MID1 mutation screening in a large cohort of Opitz G/BBB syndrome patients: twenty-nine novel mutations identified

Opitz G/BBB Syndrome (OS) is a multiple congenital anomaly disorder characterized by defects along the body midline. The disease is characterized by variable expressivity of signs that include hypertelorism, cleft lip and/or palate, laryngo-tracheo-esophageal abnormalities, cardiac defects, and hypospadias. OS patients also present with mental retardation and brain anatomical abnormalities. An autosomal dominant form mapping to chromosome 22 and an X-linked form of OS are known. The gene responsible for the X-linked form of OS, MID1, codes for a member of the Tripartite Motif family of E3 ubiquitin ligases. Here we report 29 novel mutations in 29 unrelated patients of a cohort of 140 male OS cases. These mutations are found in both familial and sporadic cases. They are scattered along the entire length of the gene and are represented by missense and nonsense mutations, insertions and deletions causing frame shift mutations, and deletion of either single exons or the entire gene. The variety of the mutations found confirms that loss-of-function is the mechanism underlying the OS phenotype. Moreover, the low percentage of MID1-mutated OS patients, 47% of the familial and 13% of the sporadic cases, suggests a wider genetic heterogeneity underlying the OS phenotype.     

MID1 mutations in patients with X-linked Opitz G/BBB syndrome

Mutations in the MID1 gene are responsible for the X-linked form of Opitz G/BBB syndrome (OS), a disorder that affects the development of midline structures. OS is characterized by hypertelorism, hypospadias, laryngo-tracheo-esophageal (LTE) abnormalities, and additional midline defects. Cardiac, anal, and neurological defects are also present. The expressivity of OS is highly variable, even within the same family. We reviewed all the MID1 mutations reported so far, in both familial and sporadic cases. The mutations are scattered along the entire length of the gene and consist of missense and nonsense mutations, insertions and deletions, either in-frame or causing frameshifts, and deletions of either single exons or the entire MID1 coding region. The variety of described mutations and the lack of a strict genotype-phenotype correlation confirm the previous suggestion of the OS phenotype being caused by a loss-of-function mechanism. However, although a specific mutation cannot entirely account for the observed phenotype, we observed preferential association between some types of mutation and specific clinical manifestations, e.g., brain anatomical defects and truncating mutations. This may suggest that the pathogenetic mechanism underlying the OS phenotype is more complex and may vary among the affected organs.     

Probable Opitz trigonocephaly C syndrome with medulloblastoma

We report on a patient with trigonocephaly, biparietal widening as a result of metopic synostosis, strabismus, upslanted palpebral fissures, apparently low-set ears with abnormal helices, deeply furrowed palate, postaxial polysyndactyly of the feet, ankle flexion deformities, cryptorchidism, loose skin, and severe mental retardation, findings compatible with a diagnosis of the Opitz trigonocephaly C syndrome (OTS). At the age of 12 years this patient presented with symptoms of raised intracranial pressure. A biopsy showed findings diagnostic of a medulloblastoma WHO Grade IV, an unprecedented finding in OTS. The possibility of coincidence should not prevent continued surveillance of OTS patients in the future for the occurrence of malignancy. Am. J. Med. Genet. 69:395–399, 1997. © 1997 Wiley-Liss, Inc.     

Linkage analysis in a family with the Opitz GBBB syndrome refines the location of the gene in Xp22 to a 4 cM region.

The Opitz GBBB syndrome (OS) is characterized in part by widely spaced inner ocular canthi and hypospadias. Recently, linkage analysis showed that the gene for the X-linked form to be located in an 18 cM region spanning Xp22. We have now conducted linkage analysis in a family previously published as having the BBB syndrome and found tight linkage to DXS7104 (Z=3.3, τ=0.0). Our data narrows the candidate region to 4 cM and should facilitate the identification and characterization of one of the genes involved in midline development.     

Opitz trigonocephaly syndrome

We report on a patient with Opitz trigonocephaly syndrome. The girl was the firstborn child of consanguineous parents and had trigonocephaly, apparent hypertelorism, upslanted palpebral fissures, strabismus, small nose with broad root, abnormally modeled ears, high palate, short neck with loose skin, polysyndactyly, and prominent clitoris and labia majora. In addition, a complex cardiovascular defect (Eisenmenger disease) was observed. The patient was mentally retarded.     

Chromosome 22q11.2 deletion in a boy with Opitz (G/BBB) syndrome

This report is on a 14-month-old boy with manifestations of Opitz (G/BBB) syndrome in whom a 22q11.2 deletion was found. Deletion analysis was requested because of some findings in this patient reminiscent of velocardiofacial (VCF) syndrome. The extent of aspiration and of respiratory symptoms in this child is not usually seen in VCF syndrome. Opitz syndrome maps to at least two loci, one on Xp, the other on 22q11.2. © 1996 Wiley-Liss, Inc.     

Concurrence of robinow syndrome and Crigler-Najar syndrome in two offspring of first cousins

We report on 3 brothers with hypertelorism, hypospadias, and tetralogy of Fallot. Parents are first cousins once removed; the father has apparent hypertelorism. An apparently normal paternal uncle who is married to a second cousin also has a daughter with hypertelorism and tetralogy of Fallot. All similarly affected relatives have mild or borderline mental retardation. The combination of anomalies may represent a previously undescribed autosomal recessive disorder.     

Apparently new “anophthalmia-plus” syndrome in sibs

The index patient of this report is a 17-weekgestation female fetus with bilateral anophthalmia, bilateral cleft lip/cleft palate, macrotia with bilateral lateral facial cleft, large open sacral neural tube defect, and uterus unicornis. Parents were normal and nonconsanguineous with an unremarkable family history. Their first child, a 4-year-old boy, is normal. The second child, a 2 ½-year-old boy, has bilateral anophthalmia and an abnormal left ear with absent lobule as the sole additional anomaly. These 2 sibs seem to be the first examples of a new “anophthalmia-plus” syndrome apparently inherited as autosomal-recessive. © 1995 Wiley-Liss, Inc.     

Toriello‐Carey syndrome: Case report with additional findings

Toriello‐Carey syndrome comprises agenesis of the corpus callosum, telecanthus, small palpebral fissures, Pierre Robin sequence, abnormal ears, nuchal laxity and cardiac defects. We report on a female patient who has some additional findings including an anteriorly placed anus. This anomaly adds to the list of other midline anomalies seen in this syndrome. We compare the findings to those seen in the Opitz BBBG syndrome, a well‐defined syndrome of the midline developmental field. Our patient, having a severe manifestation of complicated congenital heart disease, died in the neonatal period, which argues against the likelihood that this is an X‐linked disorder with more severe manifestations in males. © 2001 Wiley‐Liss, Inc.     

Novel 7‐DHCR mutation in a child with Smith‐Lemli‐Opitz syndrome

Smith‐Lemli‐Opitz syndrome (SLOS) is an autosomal recessive disorder characterized by minor facial anomalies, mental retardation, and multiple congenital abnormalities. Biochemically, the disorder is caused by deficient activity of 7‐dehydrocholesterol reductase, which catalyzes the reduction of the Δ7 double bond of 7‐dehydrocholesterol to produce cholesterol. Recently, mutations in the gene encoding 7‐dehydrocholesterol reductase (7DHCR) were found to cause SLOS. We report the first molecular characterization of an Italian SLOS patient. Interestingly, his paternal 7DHCR allele, of Arab origin, harbored a novel P329L mutation which in combination with a maternal splice‐site (IVS8‐1 G>C) mutation resulted in a relatively milder phenotype. Am. J. Med. Genet. 91:138–140, 2000. © 2000 Wiley‐Liss, Inc.     

DHCR7 genotypes of cousins with Smith‐Lemli‐Opitz syndrome

Smith‐Lemli‐Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations of the 7‐dehydrocholesterol reductase gene (DHCR7). We report on three cousins with SLOS, all of whom were found to be compound heterozygotes for the common splice site mutation IVS8‐1G→C and the missense mutation T289I. DNA analysis of one set of parents demonstrated that the father carried the missense mutation and the mother carried the IVS8–1G→C mutation. By extension, the two unrelated mothers were both heterozygous for IVS8‐1G→C. This finding supports the notion of a high carrier frequency of the IVS8‐1G→C null mutation in Northern European Caucasians. © 2001 Wiley‐Liss, Inc.     

Stratton-Parker syndrome: Confirmation of a new entity

Recently, Stratton and Parker [Am J Med Genet 32:169–173, 1989] reported on a child with a previously undescribed combination of growth hormone deficiency, wormian bones, dextrocardia, brachycamptodactyly, and other midline defects. We report on another patient with similar clinical signs. © 1994 Wiley-Liss, Inc.     

Opitz (BBB/G) syndrome: Oral manifestations

We studied a new case of the G (Opitz BBB/G) syndrome in a 12-year-old boy. Several relatives had partial manifestations of the disorder. A comprehensive dental evaluation of the propositus was conducted; included is, to our knowledge, the first published cephalometric analysis of a G syndrome patient. We reviewed 139 cases of the G syndrome; 48 of them had at least one oral abnormality. These included clefting, micrognathia, ankyloglossia, and high-arched palate. Male G syndrome patients are more likely to have oral anomalies than affected females. © 1992 Wiley-Liss, Inc.     

Incidence of Smith‐Lemli‐Opitz syndrome in Ontario,Canada

Smith‐Lemli‐Opitz syndrome (OMIM 270400) (SLOS) is caused by inherited enzymatic deficiency of 3β‐hydroxysterol‐Δ⁷‐reductase (7‐dehydrocholesterol‐Δ⁷‐reductase, DHCR7). SLOS is diagnosed clinically by the demonstration of elevated levels of 7‐dehydrocholesterol (7DHC) in body fluids or tissues. SLOS is associated with mental retardation of variable degree and severe behavior abnormalities. The physical abnormalities range from minor facial anomalies to lethal malformations of the central nervous system, heart, kidneys, and other organs. The exact incidence of SLOS is not known. Although there exist estimates of the incidence of SLOS ranging from 1 in 20,000 to 1 in 60,000, no prospective studies of the incidence of SLOS, based on the clinical data and biochemical diagnosis of SLOS, have been performed. Five unrelated cases of SLOS were diagnosed in Ontario during a 12‐month period. The diagnoses were made based on the demonstration of elevated 7DHC in plasma or amniotic fluid. The birth rate for Ontario for that period was 132,000 births. The incidence of SLOS in Ontario was at least 1 in 26,500 pregnancies in 1999–2000. Given that 86% of the population of Ontario is of European origin, the incidence of SLOS in the Ontario population of European origin was at least 1 in 22,700. As infants with mild forms of SLOS born during this period may remain undiagnosed, these numbers likely are underestimates. This observation has implications for prenatal and newborn screening for this potentially treatable inherited disorder. © 2001 Wiley‐Liss, Inc.     

Phenotypic spectrum associated with SPECC1L pathogenic variants: new families and critical review of the nosology of Teebi,Opitz GBBB,and Baraitser-Winter syndromes

The SPECC1L protein plays a role in adherens junctions involved in cell adhesion, actin cytoskeleton organization, microtubule stabilization, spindle organization and cytokinesis. It modulates PI3K-AKT signaling and controls cranial neural crest cell delamination during facial morphogenesis. SPECC1L causative variants were first identified in individuals with oblique facial clefts. Recently, causative variants in SPECC1L were reported in a pedigree reported in 1988 as atypical Opitz GBBB syndrome. Six families with SPECC1L variants have been reported thus far. We report here eight further pedigrees with SPECC1L variants, including a three-generation family, and a further individual of a previously published family. We discuss the nosology of Teebi and GBBB, and the syndromes related to SPECC1L variants. Although the phenotype of individuals with SPECC1L mutations shows overlap with Opitz syndrome in its craniofacial anomalies, the canonical laryngeal malformations and male genital anomalies are not observed. Instead, individuals with SPECCL1 variants have branchial fistulae, omphalocele, diaphragmatic hernias, and uterus didelphis. We also point to the clinical overlap of SPECC1L syndrome with mild Baraitser-Winter craniofrontofacial syndrome: they share similar dysmorphic features (wide, short nose with a large tip, cleft lip and palate, blepharoptosis, retrognathia, and craniosynostosis), although intellectual disability, neuronal migration defect, and muscular problems remain largely specific to Baraitser-Winter syndrome. In conclusion, we suggest that patients with pathogenic variants in SPECC1L should not be described as “dominant (or type 2) Opitz GBBB syndrome”, and instead should be referred to as “SPECC1L syndrome” as both disorders show distinctive, non overlapping developmental anomalies beyond facial communalities.