Magnetic Resonance Imaging for Detection of Brain Abnormalities in Fetuses with Cleft Lip and/or Cleft Palate

Objective

To determine the prevalence of brain abnormalities identified by prenatal imaging of fetuses with cleft lip with or without cleft palate (CUP) or cleft palate only (CP) and to compare with postnatal imaging and neurologic evaluation.

Design

This was a retrospective review of radiologic images (magnetic resonance imaging [MRI] and sonography) of fetuses diagnosed with CUP or CP at the Advanced Fetal Care Center at Children's Hospital Boston between 2002 and 2008. Images were reviewed for possible brain abnormalities by a pediatric radiologist who specializes in this field. Postnatal imaging was also assessed whenever available and correlated with clinical findings.

Setting

A large, tertiary-care, academic pediatric hospital.

Population

One hundred twenty-six fetuses and 105 corresponding infants.

Results

Brain abnormalities were found in 8 of 126 fetuses (6.3%) by prenatal MRI. The malformations were corpus callosal dysgenesis (n = 3), encephalocele (n = 1), hypoplasia of the cerebellar hemispheres or vermis (n = 3), and white matter neuronal migration anomaly (n = 1). An additional 2 patients were diagnosed with brain abnormalities postnatally that had not been detected on prenatal imaging.

Conclusions

The possibility of brain anomalies should be assessed in a fetus found to have CUP or CP by sonography and/or MRI. Central nervous system imaging and careful neurodevelopmental follow-up is indicated in these infants.

Deletions of NRXN1 (neurexin-1) predispose to a wide spectrum of developmental disorders

Research has implicated mutations in the gene for neurexin-1 (NRXN1) in a variety of conditions including autism, schizophrenia, and nicotine dependence. To our knowledge, there have been no published reports describing the breadth of the phenotype associated with mutations in NRXN1. We present a medical record review of subjects with deletions involving exonic sequences of NRXN1. We ascertained cases from 3,540 individuals referred clinically for comparative genomic hybridization testing from March 2007 to January 2009. Twelve subjects were identified with exonic deletions. The phenotype of individuals with NRXN1 deletion is variable and includes autism spectrum disorders, mental retardation, language delays, and hypotonia. There was a statistically significant increase in NRXN1 deletion in our clinical sample compared to control populations described in the literature (P = 8.9 x 10(-7)). Three additional subjects with NRXN1 deletions and autism were identified through the Homozygosity Mapping Collaborative for Autism, and this deletion segregated with the phenotype. Our study indicates that deletions of NRXN1 predispose to a wide spectrum of developmental disorders.

FOXE3 plays a significant role in autosomal recessive microphthalmia

FOXE3 forkhead transcription factor is essential to lens development in vertebrates. The eyes of Foxe3/foxe3-deficient mice and zebrafish fail to develop normally. In humans, autosomal dominant and recessive mutations in FOXE3 have been associated with variable phenotypes including anterior segment anomalies, cataract, and microphthalmia. We undertook sequencing of FOXE3 in 116 probands with a spectrum of ocular defects ranging from anterior segment dysgenesis and cataract to anophthalmia/microphthalmia. Recessive mutations in FOXE3 were found in four of 26 probands affected with bilateral microphthalmia (15% of all bilateral microphthalmia and 100% of consanguineous families with this phenotype). FOXE3-positive microphthalmia was accompanied by aphakia and/or corneal defects; no other associated systemic anomalies were observed in FOXE3-positive families. The previously reported c.720C > A (p.C240X) nonsense mutation was identified in two additional families in our sample and therefore appears to be recurrent, now reported in three independent microphthalmia families of varied ethnic backgrounds. Several missense variants were identified at varying frequencies in patient and control groups with some apparently being race-specific, which underscores the importance of utilizing race/ethnicity-matched control populations in evaluating the relevance of genetic screening results. In conclusion, FOXE3 mutations represent an important cause of nonsyndromic autosomal recessive bilateral microphthalmia.

Cytogenetic and array-CGH characterization of a complex de novo rearrangement involving duplication and deletion of 9p and clinical findings in a 4-month-old female

Approximately 15 patients with partial trisomy 9p involving de novo duplications have been previously described. Here, we present clinical, cytogenetic, FISH and aCGH findings in a patient with a de novo complex rearrangement in the short arm of chromosome 9 involving an inverted duplication at 9p24→p21.3 and a deletion at 9pter→p24.2. FISH probes generated from BACs selected from the UCSC genome browser were utilized to verify this rearrangement. It is likely that some previously described duplications of 9p may also be products of complex chromosomal aberrations. This report in which FISH and aCGH were used to more comprehensively characterize the genomic rearrangement in a patient with clinical manifestations of 9p duplication syndrome underscores the importance of further characterizing cytogenetically detected rearrangements.

Mitral valve prolapse in Marfan syndrome: an old topic revisited

BACKGROUND

The echocardiographic features of mitral valve prolapse (MVP) in Marfan syndrome have been well described, and the incidence of MVP in Marfan syndrome is reported to be 40-80%. However, most of the original research was performed in the late 1980s and early 1990s, when the diagnostic criteria for MVP were less specific. Our goal was to investigate the characteristics of MVP associated with Marfan syndrome using currently accepted diagnostic criteria for MVP.

METHODS

Between January 1990 and March 2004, 90 patients with definitive diagnosis of Marfan syndrome (based on standardized criteria with or without genetic testing) were referred to Massachusetts General Hospital for transthoracic echocardiography. Patients' gender, age, weight, height, and body surface area at initial examination were recorded. Mitral valve thickness and motion, the degree of mitral regurgitation and aortic regurgitation, and aortic dimensions were quantified blinded to patients' clinical information.

RESULTS

There were 25 patients (28%) with MVP, among whom 80% had symmetrical bileaflet MVP. Patients with MVP had thicker mitral leaflets (5.0 +/- 1.0 mm vs. 1.8 +/- 0.5 mm, P < 0.001), more mitral regurgitation (using a scale of 1-4, 2.2 +/- 1.0 vs. 0.90 +/- 0.60, P < 0.0001), larger LVEDD, and larger dimensions of sinus of Valsalva, sinotubular junction, aortic arch, and descending aorta indexed to square root body surface area, when compared with those without MVP. When echocardiographic features of patients younger than 18 years of age and those of patients older than 18 were compared, adult Marfan patients had larger LA dimension (indexed to square root body surface area), larger sinotubular junction (indexed to square root body surface area), and more mitral regurgitation and aortic regurgitation.

CONCLUSIONS

The prevalence of MVP in Marfan syndrome is lower than previously reported. The large majority of patients with MVP have bileaflet involvement, and those with MVP have significantly larger aortic root diameters, suggesting a diffuse disease process.

The frequency of palatal anomalies in Saethre-Chotzen syndrome

OBJECTIVE

Saethre-Chotzen Syndrome (SCS) is an autosomal dominant disorder with widespread phenotypic variability. Cardinal features include coronal synostosis, blepharoptosis, and limb abnormalities. Cleft palate can also occur, but there are few reports on its frequency. This study was undertaken to determine the prevalence of palatal anomalies in this population.

DESIGN

We retrospectively reviewed the records of 51 patients with SCS seen at Children's Hospital Boston over the past 30 years. Palatal findings in our patients were compared with those in the literature. To illustrate the phenotypic variability in SCS, we describe an unusual infant who presented for evaluation of cleft palate and blepharoptosis. Her father had only blepharoptosis; this was the clue to the diagnosis, which was confirmed by finding a deletion in the TWIST gene.

RESULTS

In our patients, high-arched palate was noted in 43%, bifid uvula in 10%, and cleft palate in 6%. These figures differed slightly from the combined percentages in published reports: 24% with high-arched palate, 2% with bifid uvula, and 5% with cleft palate.

CONCLUSIONS

Palatal anomalies are relatively common in SCS. This entity should be considered in the differential diagnosis of a child with cleft palate, particularly in the presence of blepharoptosis, nasal deviation, and limb abnormalities in the patient or in family members.

Molecular studies of segmental aneusomy: FISHing for the atypical cry in del(5)(p15.3)

We report a newborn male with multiple congenital anomalies including growth retardation, hypotonia, dysmorphic facies, widely-spaced nipples, micropenis, cryptorchidism, optic nerve hypoplasia, heart disease, and a striking, high-pitched cry. Chromosome analysis revealed de novo partial trisomy 11q due to a der(5)t(5;11)(p15.3;q22). Fluorescence in situ hybridization (FISH) showed loss of the 5p telomere signal on the der(5) chromosome, indicating the infant has partial monosomy 5p in addition to partial trisomy 11q. Among cases involving trisomy 11q, an unusual cry has only been documented in the presence of a der(5)t(5p;11q). This apparent dependence of the abnormal cry on monosomy 5p suggested the same genetic mechanism that occurs in Cri du chat syndrome (CDCS) may be responsible for the atypical cry in der(5)t(5p;11q) individuals. Neither a commercial CDCS probe (LSI D5S23, D5S721) nor a series of BAC clones encompassing distal regions implicated in the CDCS-associated cat-cry were deleted in our patient. These results suggest a second cry-modifying locus maps telomeric to BAC RP11-94J21 in band 5p15.33. This locus may not only cause the abnormal cry in individuals with a der(5)t(5p;11q) but could also contribute to the phenotypic variability and discordant mapping studies observed for CDCS.

Knowledge of and Attitudes about Alzheimer Disease Genetics: Report of a Pilot Survey and Two Focus Groups

OBJECTIVES

In preparation for the development of an educational intervention on Alzheimer disease (AD) genetics, we undertook a pilot survey of knowledge in this area and attitudes toward genetic testing for AD among individuals with a family history of AD.

METHODS

For the pilot study, we administered a 30-min questionnaire to 57 unaffected individuals from a genetic linkage study. For the focus groups, we interviewed two groups of subjects, ages 44-70 years, with a family history of AD, one of 10 Caucasians and the other of 6 African-Americans.

RESULTS

The pilot study showed that there was limited knowledge of genetics overall and AD genetics in particular, considerable concern about personal risk, and little knowledge of or interest in genetic testing for the disease. The focus groups reinforced and fleshed out these impressions and highlighted the importance of caregiving experience in the attitudes toward personal risk for AD.

CONCLUSIONS

These results underscore the value of genetics education for this and other complex diseases and suggest specific foci for educational interventions.

Bupropion in pregnancy and the prevalence of congenital malformations

PURPOSE

Reports from the GlaxoSmithKline Bupropion Pregnancy Registry suggested an increase in cardiovascular defects following exposure to bupropion during pregnancy. We conducted a study of congenital malformations among infants born to women exposed to bupropion during their first trimester.

METHODS

The study used data from UnitedHealthcare between January 1995 and September 2004. We calculated the prevalence of all congenital malformations and cardiovascular malformations associated with bupropion exposure in the estimated first trimester (1213 infants), compared with (1) other antidepressant exposure in the first trimester (4743 infants) and (2) bupropion exposure outside the first trimester (1049 infants). Malformation cases were confirmed through medical record abstraction. We calculated adjusted odds ratios (AORs) using the GEE form of logistic regression.

RESULTS

For all congenital malformations, the prevalence associated with bupropion first trimester was 23.1 per 1000 infants. The AORs were 0.95 (95%CI 0.62-1.45) and 1.00 (95%CI 0.57-1.73) in comparison to other antidepressants (prevalence 23.2 per 1000) and bupropion outside the first trimester (prevalence 21.9 per 1000), respectively. For cardiovascular malformations, the prevalence associated with bupropion first trimester was 10.7 per 1000 infants. The AORs were 0.97 (95%CI 0.52-1.80) and 1.07 (95%CI 0.48-2.40) in comparison to other antidepressants (prevalence 10.8 per 1000) and bupropion outside the first trimester (prevalence 9.5 per 1000), respectively.

CONCLUSIONS

Results do not support a hypothesis of a teratogenic effect of first trimester bupropion exposure. The prevalence of malformations associated with bupropion exposure in the first trimester was not increased relative to the comparison groups.

Patients with Ehlers Danlos syndrome and CRPS: a possible association?

Rare patients are left with chronic pain, vasodysregulation, and other symptoms that define complex regional pain syndrome (CRPS), after limb traumas. The predisposing factors are unknown. Genetic factors undoubtedly contribute, but have not yet been identified. We report four CRPS patients also diagnosed with the classical or hypermobility forms of Ehlers Danlos syndrome (EDS), inherited disorders of connective tissue. These patients had been diagnosed using standard diagnostic criteria for CRPS and for EDS. All had sustained joint injury; in three this had been surgically treated. The association of these two diagnoses leads us to hypothesize that EDS might contribute to the development of CRPS in one or more of the following ways: via stretch injury to nerves traversing hypermobile joints, increased fragility of nerve connective tissue, or nerve trauma from more frequent surgery. We review the clinical presentation of the different Ehlers Danlos syndromes and provide clinical criteria that can be used to screen CRPS patients for EDS for clinical or research purposes.

Molecular and clinical analyses of Greig cephalopolysyndactyly and Pallister-Hall syndromes: robust phenotype prediction from the type and position of GLI3 mutations

Mutations in the GLI3 zinc-finger transcription factor gene cause Greig cephalopolysyndactyly syndrome (GCPS) and Pallister-Hall syndrome (PHS), which are variable but distinct clinical entities. We hypothesized that GLI3 mutations that predict a truncated functional repressor protein cause PHS and that functional haploinsufficiency of GLI3 causes GCPS. To test these hypotheses, we screened patients with PHS and GCPS for GLI3 mutations. The patient group consisted of 135 individuals: 89 patients with GCPS and 46 patients with PHS. We detected 47 pathological mutations (among 60 probands); when these were combined with previously published mutations, two genotype-phenotype correlations were evident. First, GCPS was caused by many types of alterations, including translocations, large deletions, exonic deletions and duplications, small in-frame deletions, and missense, frameshift/nonsense, and splicing mutations. In contrast, PHS was caused only by frameshift/nonsense and splicing mutations. Second, among the frameshift/nonsense mutations, there was a clear genotype-phenotype correlation. Mutations in the first third of the gene (from open reading frame [ORF] nucleotides [nt] 1-1997) caused GCPS, and mutations in the second third of the gene (from ORF nt 1998-3481) caused primarily PHS. Surprisingly, there were 12 mutations in patients with GCPS in the 3' third of the gene (after ORF nt 3481), and no patients with PHS had mutations in this region. These results demonstrate a robust correlation of genotype and phenotype for GLI3 mutations and strongly support the hypothesis that these two allelic disorders have distinct modes of pathogenesis.

Successful long-term treatment of hepatic carnitine palmitoyltransferase I deficiency and a novel mutation

Individuals with carnitine palmitoyltransferase I (CPT-I) deficiency cannot metabolize long-chain fatty acids and can develop life-threatening hypoglycaemia. We present a boy with CPT-I deficiency maintained on a very low-fat diet with nighttime uncooked cornstarch feedings for 5(1/2) years with good success. He has had normal growth and no episodes of hypoglycaemia or adverse side-effects. We found that he was homozygous for a previously undescribed mutation, T314I, in the CPT1A protein.

Alcohol dehydrogenase 2 genotypes, maternal alcohol use, and infant outcome

OBJECTIVE

To determine whether different alleles of the ADH2 gene (ADH2-1, ADH2-2 and ADH2-3) with differing levels of enzymatic activity can alter the risk of fetal alcohol effects.

STUDY DESIGN

ADH2 genotypes were performed on 404 pregnant high-risk women and 139 infants as part of a larger study of alcohol use in pregnancy. Mothers were interviewed about alcohol use during pregnancy, and their infants were examined for alcohol-related features without knowledge of the exposure status.

RESULTS

The ADH2-1/3 genotype was more prevalent among black women (46%) than expected (33%); the rate among white women was low as expected (2%). More black women who reported high alcohol use during the pregnancy had the ADH2-1/3 genotype compared with those who reported no alcohol use (70% vs 44%). Sixty percent of the affected black infants had the ADH2-1/3 genotype compared with 29% of the unaffected infants (P <.045). The maternal genotype correlated with her chance of having an infant with alcohol-related physical features (odds ratio = 2.49). This association remained significant after accounting for confounders, such as smoking and maternal weight gain. Alcohol exposure was not significantly associated with infant outcome in black infants after accounting for genotype, smoking, and maternal weight gain, but this association could only be tested in 10 infants of mothers with high exposure.

CONCLUSION

Women with the ADH2-1/3 genotype may be at greater risk for having an affected infant, which may be the result of greater ingestion of alcohol.

Maternal antiepileptic drug use and effects on fetal development

Many pregnant women take antiepileptic medications, and concern has arisen about the risks this poses to the fetus. It has been debated whether the causative agent is the medication or the underlying maternal disorder. Review of the recent literature indicates that the effects seem to be from the medications themselves. The frequency of malformations is about two to three-fold above the background rate and is dose-related for some of the medications. There seem to be effects on birth weight, length, and head circumference caused by at least some of the medications. The risks are greater when more than one medication is used. Cognitive effects from the medications have been shown, although these effects are of lower magnitude than previously reported. More investigation needs to be done to determine the exact risks of each individual medication, especially the newer ones. Studies on underlying mechanisms indicate potential genetic susceptibility and altered developmental gene expression patterns.

Malformations reported in chorionic villus sampling exposed children: a review and analytic synthesis of the literature

PURPOSE

To determine whether the frequency of vascular disruption defects, other than limb defects, is increased in reports of chorionic villus sampling (CVS) exposed children compared with an unexposed population.

METHODS

Only studies that reported the total number of CVS-exposed pregnancies and details of pregnancy outcome, including all the malformations, were included. Twenty-five articles met these criteria.

RESULTS

The frequencies of gastroschisis, intestinal atresias, and clubfoot were significantly increased among the CVS-exposed infants as compared with the baseline unexposed population. The frequencies of other vascular disruption defects, including Poland sequence, amniotic band sequence, and cleft lip/cleft palate, were not increased.

CONCLUSION

CVS-exposed children have an increased frequency of intestinal atresia, gastroschisis, and clubfoot compared with the nonexposed population. The fact that an increased frequency of other defects attributed to vascular disruption was not found may be due to under-ascertainment, misclassification, or "lumping" of the defects identified in previous studies.

Under-recognition of prenatal alcohol effects in infants of known alcohol abusing women

Medical records of 124 women and their infants were analyzed for: (1) documentation of maternal alcohol and other substance abuse and (2) evaluation of exposed infants. These results were compared with the study interview and infant examination. More obstetric nurses documented the presence or absence of alcohol and substance abuse than did pediatricians. More women reported using alcohol in the study interview than documented in the medical records. There was slightly better documentation for cocaine use than for alcohol use in the medical records. One of the 19 infants with documentation of maternal alcohol use was noted to have possible alcohol-related features by the pediatrician, in contrast to 7 infants identified by the study examiner. In addition, 2 of these 19 infants were determined by the study examiner to have fetal alcohol syndrome; neither case was diagnosed by the pediatricians. Continued efforts at education regarding the importance of asking about prenatal alcohol exposure and the spectrum of fetal alcohol effects are needed for early diagnosis.