Deletions involving long-range conserved nongenic sequences upstream and downstream of FOXL2 as a novel disease-causing mechanism in blepharophimosis syndrome.

The expression of a gene requires not only a normal coding sequence but also intact regulatory regions, which can be located at large distances from the target genes, as demonstrated for an increasing number of developmental genes. In previous mutation studies of the role of FOXL2 in blepharophimosis syndrome (BPES), we identified intragenic mutations in 70% of our patients. Three translocation breakpoints upstream of FOXL2 in patients with BPES suggested a position effect. Here, we identified novel microdeletions outside of FOXL2 in cases of sporadic and familial BPES. Specifically, four rearrangements, with an overlap of 126 kb, are located 230 kb upstream of FOXL2, telomeric to the reported translocation breakpoints. Moreover, the shortest region of deletion overlap (SRO) contains several conserved nongenic sequences (CNGs) harboring putative transcription-factor binding sites and representing potential long-range cis-regulatory elements. Interestingly, the human region orthologous to the 12-kb sequence deleted in the polled intersex syndrome in goat, which is an animal model for BPES, is contained in this SRO, providing evidence of human-goat conservation of FOXL2 expression and of the mutational mechanism. Surprisingly, in a fifth family with BPES, one rearrangement was found downstream of FOXL2. In addition, we report nine novel rearrangements encompassing FOXL2 that range from partial gene deletions to submicroscopic deletions. Overall, genomic rearrangements encompassing or outside of FOXL2 account for 16% of all molecular defects found in our families with BPES. In summary, this is the first report of extragenic deletions in BPES, providing further evidence of potential long-range cis-regulatory elements regulating FOXL2 expression. It contributes to the enlarging group of developmental diseases caused by defective distant regulation of gene expression. Finally, we demonstrate that CNGs are candidate regions for genomic rearrangements in developmental genes.

Maternal uniparental disomy 7--review and further delineation of the phenotype.

UNLABELLED: Uniparental disomy (UPD) is defined as the inheritance of both homologous chromosomes from only one parent. So far, maternal UPD 7 has been described in 28 cases. Here, we report 4 new cases, present clinical information of 5 cases previously reported by us, and review the clinical and molecular findings of all 32 cases. We found a phenotype characterized by pre- and postnatal growth retardation, occipitofrontal head circumference in the lower normal range, a triangular face, and retarded bone maturation. Findings of the facial gestalt included a high and broad forehead and a pointed chin. A broad mouth with down-turned corners, prominent ears, café-au-lait spots, hemihypotrophy, or clinodactyly were rarely present. Psychomotor development was delayed in 6 cases. The clinical findings strikingly resemble the phenotype of the heterogeneous Silver-Russell syndrome (SRS). Other anomalies were less frequently found than in SRS. Molecular investigations revealed 11 cases with isodisomy and 17 cases with heterodisomy. In 4 cases this information was not available. From the allelic distribution of the microsatellites investigated, 9 cases might be the consequence of an error at maternal meiosis I, and 6 cases might be due to non-disjunction at maternal meiosis II. Three of the 17 heterodisomic cases had trisomy 7 in chorionic villi, in the remaining cases no prenatal diagnosis through chorionic villus sampling was reported. CONCLUSION: Maternal UPD 7 should investigated in children with pre- and postnatal growth retardation anda facial gestalt characterized by a high and broad forehead and a pointed chin, as well as in cofined placental mosaicism for trisomy 7.

"New" ectodermal dysplasia with mental retardation and syndactyly.

We describe a girl with an unusual form of ectodermal dysplasia. She was mildly mentally retarded, had normal height, weight, and head circumference, a large scalp defect, a peculiar face with large palpebral fissures, a broad nasal bridge and constantly open mouth, abnormally-modeled ears, syndactyly of fingers/toes, mild hypohidrosis, and severe onychogryposis. Her hair was short, abundant, and stiff, her eyebrows were sparse, and her skin was dry. Analysis of the literature showed that this type of association of ectodermal dysplasia and other defects has not been previously described.

Uniparental disomy 7 in Silver-Russell syndrome and primordial growth retardation.

Maternal uniparental disomy for the entire chromosome 7 has so far been reported in three patients with intrauterine and postnatal growth retardation. Two were detected because they were homozygous for a cystic fibrosis mutation for which only the mother was heterozygous, and one because he was homozygous for a rare COL1A2 mutation. We investigated 35 patients with either the Silver-Russell syndrome or primordial growth retardation and their parents with PCR markers to search for uniparental disomy 7. Four of 35 patients were found to have maternal disomy, including three with isodisomy and one with heterodisomy. The data confirm the hypothetical localization of a maternally imprinted gene (or more than one such gene) on chromosome 7. It is suggested to search for UPD 7 in families with an offspring with sporadic Silver-Russell syndrome or primordial growth retardation.

Kabuki make-up (Niikawa-Kuroki) syndrome in the Byelorussian register of congenital malformations: ten new observations.

We describe clinical manifestations and historical data on ten patients with Kabuki make-up syndrome. All patients are of European ancestry and all have the characteristics of the syndrome, including typical face, retarded physical development, and mild to moderate mental retardation. Two of the probands have low-normal intelligence. Prominent and broad philtrum was described as an important component manifestation of the syndrome. In three families some clinical manifestations of Kabuki make-up syndrome were observed in parents and some other relatives of the probands in three generations. Some phenotypic differences between Asian and non-Asian patients were noted. The possible cause of the syndrome is discussed. The present observations and a literature review suggest autosomal dominant inheritance with different expressivity of the Kabuki make-up syndrome.

Trisomy 2p: analysis of unusual phenotypic findings.

We present three probands with partial trisomies 2p21-23 due to ins(4;2)(q21;p21p23) pat, 2p23-pter due to t(2;4)(p23;q35)mat, and 2p21-pter due to t(2;11)(p21;q23.3)mat. More than 50 cases of partial trisomy 2p have been reviewed and some abnormalities, unusual for most other types of structural autosomal imbalance, have been found in patients with inherited forms of 2p trisomy and in their non-karyotyped sibs. Neural tube defects (anencephaly, occipital encephalocele, and spina bifida) were found in five probands and 4/6 affected non-karyotyped sibs. The only triplicated segment common to all was 2p24. Different forms of "broncho-pulmonary a/hypoplasia" (including two cases of lung agenesis) were described in four patients (overlapping triplicated segment was 2p21-p25). Three patients (with overlapping triplicated segment 2p23-p25) had diaphragmatic hernia. Abnormal rotation of the heart or L-transposition of large vessels (with or without visceral heterotaxia) was found in two infants (overlapping triplicated segment 2p23-p24). In two patients with common triplicated segment 2p22.3-p25, neuroblastoma has been described. The occurrence of all these defects may be explained either by the action of the same gene(s) mapped to 2p24 or by action of some independent factors located in different segments of the short arm. Although the latter hypothesis is much less probable, it can not be rejected at the present time. We propose the existence of a genetic system controlling surveillance of an abnormal embryo to explain the phenotypic differences between patients with the same imbalance within a family. In some "restrictive" combinations the abnormal embryos will die, although in "permissive" combinations they can survive.

Dubowitz syndrome: possible evidence for a clinical subtype.

Clinico-genetic analysis of 21 personal observations and review of the literature confirmed the existence of a wide phenotypic spectrum of Dubowitz syndrome. It is shown that in spite of marked microcephaly, severe mental deficiency is rare in Dubowitz syndrome and about half of the patients are mentally normal. A "new" clinical subtype is defined, which also includes anorectal anomalies and premature craniosynostosis. All three families with this form are natives of a small area of Byelorussia, suggesting an autosomal or X-linked recessive mode of inheritance of this subtype. The data obtained confirm autosomal recessive inheritance of Dubowitz syndrome.

Chromosome 7 abnormalities in parents of children with holoprosencephaly and hydronephrosis.

At least nine cases of holoprosencephaly (HPE) found in patients with confirmed loss of 7q34----7qter or 7q36----7qter have been reported in the literature. In the present report, balanced rearrangements involving chromosome 7q [inv(7)(p22.1q34) and t(4;7)(q31;q36)] were shown in two mothers examined after the birth of their non-karyotyped infants with HPE and hydronephrosis. In both cases, del(7q) was the most probable imbalance. The available data confirm the association between HPE and del(7q). Predominance of cyclopia and cebocephaly, the severest forms of HPE, suggests that del(7q) may be an important factor in arresting prosencephalon development at the earliest stages.