Victoria A. Cox

Congenital diaphragmatic defects and associated syndromes, malformations, and chromosome anomalies: a retrospective study of 60 patients and literature review.

Congenital diaphragmatic defects (CDDs) may occur in malformation syndromes of varied causes. Syndromic cases of CDDs due to chromosomal defects, autosomal recessive, autosomal dominant, or X-linked inheritance have been described. In order to determine the frequency and nature of syndromes, malformations, and chromosome abnormalities associated with CDDs, we reviewed the records of all patients with CDDs evaluated over a 4-year period. During the 4-year interval, a total of 60 patients was evaluated. Of these, 29 had a therapeutic or spontaneous abortion, and 31 received postnatal care. On prenatal ultrasonography, 20 of 60 (33%) of patients with CDDs had additional anomalies. Additional anomalies, besides CDDs, were present in 15 of 31 (48%) of liveborn patients on newborn evaluation. In total, 16 patients with multiple anomalies were evaluated. Of these, 12 of 16 (75%) had additional abnormalities detected by prenatal ultrasonography. The 4 of 16 (25%) without additional anomalies on prenatal sonography had multiple anomalies found neonatally, lethal multiple pterygium syndrome being diagnosed in one case. Prenatal chromosome analysis was performed in 7 of 16 patients, and all had postnatal karyotypes. All initial karyotypes were normal. Tetrasomy 12p was documented on postnatal fibroblast analysis in one case who had percutaneous umbilical blood sampling (PUBS). Syndromes diagnosed postnatally in 7 of 16 patients (44%) include: Fryns syndrome (2), Simpson-Golabi-Behmel syndrome (2), tetrasomy 12p (1), Brachmann-de Lange syndrome (1), and lethal multiple pterygium syndrome (1). We were unable to make a specific diagnosis in 9 of 16 patients (56%) with multiple malformations. In patients with CDDs, a normal prenatal karyotype, especially if obtained by PUBS, and absence of other detected abnormalities by fetal ultrasonography, do not exclude the presence of other major anomalies, including chromosome abnormalities and severe multiple malformation syndromes.

Apparent cyclophosphamide (cytoxan) embryopathy: A distinct phenotype?

Cyclophosphamide (CP) is an alkylating agent widely used in treating cancer and autoimmune disease. CP is classified as a pregnancy risk factor D drug and is teratogenic in animals, but population studies have not conclusively demonstrated teratogenicity in humans. Six isolated reports of prenatally exposed infants with various congenital anomalies exist, but to date no specific phenotype has been delineated. The purpose of this report is to document a new case of in utero CP exposure with multiple congenital anomalies and to establish an apparent CP embryopathy phenotype. The mother had systemic lupus erythematosus and cyclophosphamide exposure in the first trimester. She also took nifedipine, atenolol, clonidine, prednisone, aspirin, and potassium chloride throughout pregnancy. The infant had growth retardation and multiple anomalies including microbrachycephaly, coronal craniosynostosis, hypotelorism, shallow orbits, proptosis, blepharophimosis, small, abnormal ears, unilateral preauricular pit, broad, flat nasal bridge, microstomia, high-arched palate, micrognathia, preaxial upper limb and postaxial lower limb defects consisting of hypoplastic thumbs, and bilateral absence of the 4th and 5th toes. Chromosomes were apparently normal. The reported cases of in utero exposure to cyclosposphamide shared the following manifestations with our patient: growth deficiency, developmental delay, craniosynostosis, blepharophimosis, flat nasal bridge, abnormal ears, and distal limb defects including hypoplastic thumbs and oligodactyly. We conclude that (a) cyclophosphamide is a human teratogen, (b) a distinct phenotype exists, and (c) the safety of CP in pregnancy is in serious question.

Oculoauriculovertebral Abnormalities in Children of Diabetic Mothers

Maternal diabetes is known to have teratogenic effects. Malformations including neural tube defects, caudal dysgenesis, vertebral defects, congenital heart defects, femoral hypoplasia, and renal anomalies are described in infants of diabetic mothers. However, craniofacial anomalies have rarely been reported in such infants. Here we document craniofacial anomalies of patients born to diabetic mothers. We describe two patient populations: individuals evaluated through our genetics services for multiple malformations and individuals identified through a database search in our craniofacial clinic. The first group consists of 14 individuals evaluated in our genetics clinics who were born to diabetic mothers and had craniofacial anomalies. The second group consists of seven individuals who were identified from a craniofacial database search of patients with hemifacial microsomia and who were born to diabetic mothers. Thus, both groups were born to diabetic mothers and had hemifacial microsomia (67%), microtia (52%), hearing loss (43%), epibulbar dermoids (24%), and fused cervical vertebrae (24%). Therefore, the teratogenic effects of maternal diabetes probably include such craniofacial malformations as the oculoauriculovertebral/Goldenhar complex. Infants of diabetic mothers should be evaluated for craniofacial anomalies. Conversely, mothers of infants with craniofacial anomalies should be evaluated for diabetes to aid in counseling concerning cause and recurrence risks.

Severe congenital anomalies requiring transplantation in children with Kabuki syndrome

Kabuki syndrome (KS) is a rare multiple malformation disorder characterized by developmental delay, distinct facial anomalies, congenital heart defects, limb and skeletal anomalies, and short stature. Renal anomalies have been reported in a few cases of KS, but to our knowledge, hepatic anomalies have not. Here, we document two cases of KS requiring liver or kidney transplantation: one with severe hepatic and renal anomalies and one with severe renal anomalies. Both cases had the characteristic facial appearance of children with KS, postnatal growth deficiency, and developmental delay. At birth, case 1 presented with hypoglycemia, ileal perforation, right hydroureter, and hydronephrosis. The patient subsequently developed hyperbilirubinemia, hepatic abscess, and cholangitis. At age 8 months, he underwent a liver transplant. Hepatic pathology diagnosed neonatal sclerosing cholangitis. Case 2 presented with renal failure at age 6 years. Renal ultrasound study showed markedly dysplastic kidneys requiring transplantation. In addition to characteristic findings of KS, she had coronal synostosis and was shown to have immune deficiency and an autoimmune disorder manifesting as Hashimoto thyroiditis and vitiligo. We conclude: 1) severe hepatic and renal anomalies leading to organ failure can occur in KS; 2) patients with neonatal sclerosing cholangitis should be examined closely for features of KS; 3) coronal synostosis may occur in KS; and 4) immune deficiency and autoimmune disorder can be associated with KS.

Cardio–facio–cutaneous syndrome phenotype in an individual with an interstitial deletion of 12q: Identification of a candidate region for CFC syndrome

We report on a 19-month-old girl who presented with the phenotype of cardio-faciocutaneous (CFC) syndrome including characteristic minor facial anomalies, cardiac defect, ectodermal anomalies, and developmental delay. Cytogenetic analysis showed the presence of an interstitial deletion of one chromosome 12, del(12)(q21.2q22), confirmed by fluorescence in situ hybridization with chromosome band specific probes. Controversy exists as to whether CFC and Noonan syndrome (NS) are distinct disorders, a contiguous gene syndrome, or allelic variants. The identification of the del(12) in this patient, in a region distinct from the putative NS locus, supports the view that CFC is a genetically distinct condition from NS. In addition, this implicates the region 12q21.2-->4q22 as a candidate region for the gene(s) causing CFC syndrome.

True trisomy 2 mosaicism in amniocytes and newborn liver associated with multiple system abnormalities

Among 58,000 amniocenteses completed, our laboratories found one case of true cytogenetic trisomy 2 mosaicism in a fetus with multiple abnormalities. In contrast, 11 fetuses phenotypically normal at birth were found to have true trisomy 2 mosaicism in their chorionic villus cells among the 10,500 fetuses tested by chorionic villus sampling (CVS). In our single abnormal case, amniocentesis performed at 19 weeks after finding an elevated maternal serum AFP found two independent cultures with trisomy 2 karyotypes in 8 of 25 and 7 of 31 amniocytes, respectively. Although oligohydramnios was noted by ultrasound, the mother elected to continue the pregnancy. At 26 weeks the fetus had intrauterine growth retardation (IUGR), hydronephrosis, and cardiac abnormalities. When delivered by Cesarean section at 30 weeks, the infant had multiple anomalies and developed necrotizing enterocolitis and severe cholestasis. At 5 months coronal magnetic resonance imaging (MRI) displayed delayed myelination and abnormal brain morphology. The patient also exhibited significant growth failure and developmental delay. Although chromosomes were normal in blood, skin fibroblasts, and ascites fluid cells, 4 of 100 hepatic biopsy fibroblasts were 47,XY,+2. Molecular analysis excluded uniparental disomy (UPD) of chromosome 2 in the 46,XY cell line. This and other reports of rare phenotypically abnormal trisomy 2 mosaic fetuses identified by karyotyping amniocytes emphasizes the substantially higher fetal risk of abnormal development than when trisomy 2 is found only in chorionic villus cells.

Further clinical and molecular delineation of the 15q24 microdeletion syndrome

Background Chromosome 15q24 microdeletion syndrome is a rare genomic disorder characterised by intellectual disability, growth retardation, unusual facial morphology and other anomalies. To date, 20 patients have been reported; 18 have had detailed breakpoint analysis. Aim To further delineate the features of the 15q24 microdeletion syndrome, the clinical and molecular characterisation of fifteen patients with deletions in the 15q24 region was performed, nearly doubling the number of reported patients. Methods Breakpoints were characterised using a custom, high-density array comparative hybridisation platform, and detailed phenotype information was collected for each patient. Results Nine distinct deletions with different breakpoints ranging in size from 266 kb to 3.75 Mb were identified. The majority of breakpoints lie within segmental duplication (SD) blocks. Low sequence identity and large intervals of unique sequence between SD blocks likely contribute to the rarity of 15q24 deletions, which occur 8–10 times less frequently than 1q21 or 15q13 microdeletions in our series. Two small, atypical deletions were identified within the region that help delineate the critical region for the core phenotype in the 15q24 microdeletion syndrome. Conclusion The molecular characterisation of these patients suggests that the core cognitive features of the 15q24 microdeletion syndrome, including developmental delays and severe speech problems, are largely due to deletion of genes in a 1.1–Mb critical region. However, genes just distal to the critical region also play an important role in cognition and in the development of characteristic facial features associated with 15q24 deletions. Clearly, deletions in the 15q24 region are variable in size and extent. Knowledge of the breakpoints and size of deletion combined with the natural history and medical problems of our patients provide insights that will inform management guidelines. Based on common phenotypic features, all patients with 15q24 microdeletions should receive a thorough neurodevelopmental evaluation, physical, occupational and speech therapies, and regular audiologic and ophthalmologic screening.

Homozygosity for a FBN1 missense mutation causes a severe Marfan syndrome phenotype.

To the Editor : Marfan syndrome (OMIM 154700) is a connective tissue disorder involving the cardiovascular, ocular, and skeletal systems caused by heterozygous mutations in FBN1 . It is autosomal dominant with clinical variability partially explained by allelic heterogeneity (1). Individuals with biallelic FBN1 mutations provide insight into molecular mechanisms and clinical care of Marfan syndrome. We report a woman with severe Marfan syndrome homozygous for a previously unreported FBN1 missense mutation. The proband is a Mexican-American woman born from a consanguineous union (F = 0.25). She was thin with a pectus carinatum, scoliosis, arachnodactyly, dislocated lenses, mitral valve prolapse, aortic dilatation, dural ectasias, and anterior sacral meningocele. Brain imaging revealed low lying cerebellar tonsils and moderate hydrocephalus. Her scoliosis worsened, her ocular lenses were extracted, she developed urethral prolapse and neurogenic bladder, and an eye was enucleated for glaucoma. She had mild cognitive impairment. At 18 years of age, her height was 155 cm (10th percentile), span to height ratio was 1.05, and she had a narrow, asymmetric face, dolichocephaly, hypertelorism with an interpupillary distance of 6.4 cm (97th percentile), down-slanting palpebral fissures, kyphoscoliosis, narrow palate, positive wrist and thumb signs, arachnodactyly with middle finger length of 8.4 cm (97th percentile), and mild joint contractures (Fig. 1). Clinical sequencing of FBN1 revealed homozygosity for a single base pair substitution, c.7726C>T, predicting p.Arg2576Cys (transcript NM_000138.4). She became pregnant at 20 years of age. Her aortic root was 4.3 cm at 14 weeks gestation. At 30 weeks she developed chest pain and dyspnea. Computerized tomography scan revealed new aortic insufficiency and dilatation. Cesarean section and aortic root repair of a type A dissection were performed. Her son was small for gestational age but healthy. He had dolichocephaly, down-slanting palpebral fissures, midface hypoplasia, high narrow palate, and mild right knee contracture. Ophthalmology exam and echocardiogram were normal. Mutation testing has not been performed, but heterozygosity has been assumed. The proband’s mother lacks examination findings of Marfan syndrome and had a normal optometry examination. Mutation analysis confirmed her to be heterozygous for c.7726C>T. The proband’s father had a cardiac event attributed to drug abuse although aortic dissection cannot be excluded. He reportedly had no other features of Marfan syndrome, but was unavailable for the examination. Patients from five families have been reported with confirmed homozygosity or compound heterozygosity for FBN1 mutations (Table 1) (2–5). In each case, the individual with two FBN1 mutations exhibited more severe manifestations than their heterozygous family members. In addition, heterozygous parents in several families lacked or had only mild Marfan syndrome manifestations. The proband’s mutation has not been reported in the medical literature but was seen in another patient tested at the same clinical laboratory. It is predicted to be disease causing by Mutation Taster (p = 0.999) and probably damaging by Polyphen-2

Brachydactylic multiple delta phalanges plus syndrome

Delta phalanges are unusual, shortened bones of the hands and feet with abnormal epiphyses and diaphyses. Here, we report on a patient with a unique multiple congenital anomaly syndrome that includes brachydactyly consisting of multiple delta phalanges in several digits of the hands and feet. The patient, who was born to consanguineous parents, had several other congenital anomalies, including butterfly vertebrae, craniofacial dysmorphism, and coarctation of the aorta. We have called this distinctive condition “brachydactylic multiple delta phalanges plus syndrome.” Although no other member of the family had obvious hand or foot anomalies, several siblings had other malformations. Possible modes of inheritance in this family include variable expression of a recessive or de novo dominant condition.