Scanning for telomeric deletions and duplications and uniparental disomy using genetic markers in 120 children with malformations

We screened 120 children with sporadic multiple congenital anomalies and either growth or mental retardation for uniparental disomy (UPD) or subtelomeric deletions. The screening used short tandem repeat polymorphisms (STRP) from the subtelomeric regions of 41 chromosome arms. Uninformative marker results were reanalyzed by using the next available marker on that chromosome arm. In total, approximately 25,000 genotypes were generated and analyzed for this study. Subtelomeric deletions of 1 Mb in size were excluded for 27 of 40 chromosome arms. Among the 120 subjects none was found to have UPD, but five subjects (4%, 95% confidence interval 1-9%) were found to have a deletion or duplication of one or more chromosome arms. We conclude that UPD is not a frequent cause of undiagnosed multiple congenital anomaly syndrome. In addition, we determined that 9p and 7q harbor chromosome length variations in the normal population. We conclude that subtelomeric marker analysis is effective for the detection of subtelomeric duplications and deletions, although it is labor intensive. Given a detection rate that is similar to prior studies and the large workload imposed by STRPs, we conclude that STRPs are an effective, but impractical, approach to the determination of segmental aneusomy given current technology.

Neurodevelopmental and neuroimaging correlates in nonsyndromal microcephalic children

This descriptive study examined the relationship between head size, developmental functioning, and neuroimaging findings in children with absolute microcephaly. Subjects, aged 1 to 48 months, were assigned to one of two groups based on occipitofrontal head circumference (OFC). Group A included subjects with an OFC of 2 to 2.99 standard deviations below the mean, and Group B included subjects with an OFC of 3 or more standard deviations below the mean. Brain scan findings for 62% of the subjects were abnormal. Findings included cerebral atrophy, cortical dysplasia, myelination delay, and white matter hypoplasia. Mean scores for developmental measures in Groups A and B were less than 70. Mean developmental scores in the normal imaging group were 70 or greater, whereas developmental scores in the abnormal imaging group were 52 or less. Forty-three percent of the subjects in Group A and 80% of those in Group B had abnormal findings from imaging studies (p = .0394). Subjects with one or more brain abnormalities determined on the basis of magnetic resonance images or computed tomographic scans had significantly lower scores in all developmental areas (p < .05). The authors concluded that abnormal brain images seem to be a better reflection of developmental performance than the degree of microcephaly. J Dev Behav Pediatr 21:12-18, 2000. Index terms: microcephaly, neuroimaging, neurodevelopment.

Familial occurrence of congenital aneurysm of the muscular interventricular septum

Congenital aneurysms of the muscular interventricular septum are rare. We report two brothers with this disease and their father, who had marked thinning of part of the muscular interventricular septum with paradoxical motion. These cases lend support to the idea that these aneurysms are the result of an inherited defect in the myocardium.

Otologic manifestations of Wolf-Hirschhorn syndrome

OBJECTIVE

To determine if haploinsufficiency for chromosome 4p16.3 in Wolf-Hirschhorn syndrome (WHS) is associated with cochlear hearing loss.

DESIGN

Case series.

SETTING

Tertiary care center.

PATIENTS

Six patients with WHS were identified through a database and charts were retrospectively reviewed.

MAIN OUTCOME MEASURES

Presence of sensorineural hearing loss as assessed by brainstem auditory evoked response.

RESULTS

One of the 6 patients had sensorineural hearing loss. Three of the 6 patients had chronic otitis media with effusion and underwent bilateral tympanostomy tube placement; 2 of these 3 had cleft lip and palate, and 1 had a bifid uvula. One of the 6 patients had spontaneous nystagmus. Five of the 6 patients had preauricular and/or auricular abnormalities.

CONCLUSIONS

More than 25 genes for nonsyndromic hereditary hearing impairment have been mapped. One of these genes, DFNA6, was identified through linkage analysis of a family with dominant, progressive, low-frequency sensorineural hearing loss. DFNA6 maps to chromosome 4p16.3, a region that is partially deleted in patients with WHS. In our series, we identified the second patient with WHS in the literature with bilateral sensorineural hearing loss. The incidence and type of otologic findings are consistent with those reported in the literature. Analysis of patients with chromosomal rearrangements represents one strategy toward identifying candidate genes for genetic hearing impairment.

Acampomelic campomelic dysplasia: further radiographic variations

Acampomelic campomelic dysplasia (ACD) is a rare genetic syndrome affecting bone and connective tissue. This syndrome is a variant of the more commonly encountered campomelic dysplasia but is characterized by the absence of long bone curvature (acampomelia). Affected children have a characteristically flat facial profile and present with respiratory distress. They all have markedly hypoplastic scapulae. We present two sisters with ACD between whom there were some clinical and radiographic differences and also variations from the classic CD. We describe shallow orbits, a radiographic finding that has not been previously documented in this dysplasia.

Neurodevelopmental profile of infants and toddlers with oculo-auriculo-vertebral spectrum and the correlation of prognosis with physical findings

We studied the neurodevelopmental profile of infants and toddlers with oculo-auriculo-vertebral spectrum (OAV) and determined if certain physical manifestations were indicative of a poor neurodevelopmental prognosis. Twenty-four patients with OAV, aged birth to 57 months, were seen in the Department of Medical Genetics at Children's National Medical Center for multidisciplinary evaluations, including neurodevelopmental assessments. Fifty-eight percent of these children scored more than 2 standard deviations below the mean in at least one domain of development. There was no difference in developmental outcome of boys versus girls, children affected unilaterally on the right side versus left side, and those with severe clinical manifestations versus those with a milder form. Children with OAV and abnormal muscle tone had lower cognitive, gross motor, and expressive language scores (P = 0.05, P = 0.002, and P = 0.02, respectively). Those affected bilaterally had lower cognitive, fine motor, receptive language, and expressive language scores (P = 0.06, P = 0.03, P = 0.03, P = 0.02, respectively). Children with cervical spine abnormalities had lower cognitive, fine motor, and expressive language scores (P = 0.02, P = 0.04, and P = 0.04, respectively). We conclude that infants and toddlers with OAV are at increased risk for neurodevelopmental delay, especially those with abnormal muscle tone, bilateral involvement, and cervical vertebral anomalies. The complexity of the neurodevelopmental problems is strongly suggestive of central nervous system disturbances. Patients with OAV need comprehensive evaluation by a multidisciplinary team to define potential neurodevelopmental delays, allow for early intervention services, and promote an optimal developmental outcome.

Patient with craniosynostosis and marfanoid phenotype (Shprintzen-Goldberg syndrome) and cloverleaf skull

Marfanoid phenotype with craniosynostosis (Shprintzen-Goldberg syndrome) is a rare disorder previously described in only 5 patients. We report on the sixth known patient with this condition. The findings which distinguish our patient from others reported previously are that she was ascertained prenatally as having a cloverleaf skull; this is the first female patient described with this condition. Postnatally, she presented with arachnodactyly, camptodactyly, and clover-leaf skull. Imaging studies of the brain documented microcephaly with malformed brain, hydrocephaly, and hypoplasia of the corpus callosum. She also had choanal atresia and stenosis, a clinical finding previously reported only once, in this disorder.

Frontometaphyseal dysplasia: neonatal radiographic diagnosis

Frontometaphyseal dysplasia (FMD) is an uncommon genetic syndrome affecting bone and connective tissue. This condition is characterized by hyperostosis of the skull and prominence of the supraorbital ridges; long bones have flared metaphyses. Frontometaphyseal dysplasia is an X-linked dominant trait with more severe manifestations in males and with extreme variability in females. Diagnosis in the neonatal period is difficult. We present 2 newborn boys with the radiographic findings of FMD.

Ocular findings in a family with Sotos syndrome (cerebral gigantism)

PURPOSE/METHODS

We examined the ocular features in a two-generation family with Sotos syndrome (cerebral gigantism). Sotos syndrome is characterized by excessive growth in prenatal and early life, advanced bone age, and typical facial features.

RESULTS/CONCLUSION

One patient had presenile nuclear sclerotic cataracts, megalophthalmos, hypoorbitism, and exotropia. One of her daughters had megalocornea, exophoria, and iris hypoplasia. Her other daughter had megalocornea. The ophthalmologist can play an important role in the diagnosis and treatment of Sotos syndrome.

Variable prenatal appearance of osteogenesis imperfecta

Osteogenesis imperfecta is a heterogeneous group of disorders of type I collagen with both lethal and nonlethal forms. Prenatal sonographic findings in affected fetuses are variable and depend on the severity of the disease. Six cases of osteogenesis imperfecta in which prenatal sonography had been performed were reviewed. Two cases of lethal type II osteogenesis imperfecta revealed short femurs at 16 to 17 weeks' gestation with development of bowing and fractures by 19 weeks' gestation. Four fetuses with the nonlethal type III or IV had femoral bowing with or without shortening in the late second or third trimester with grossly normal mineralization. Fractures in this latter group did not develop until 1 to 12 months after delivery. Understanding the progressive nature and variability of osteogenesis imperfecta is crucial in the prenatal diagnosis and management of this disease.

Persistent pulmonary hypertension in newborn infants with cogenital myotonic dystrophy

We describe two infants with congenital myotonic dystrophy that was complicated by persistent pulmonary hypertension. Both infants died of respiratory insufficiency that was unresponsive to ventilatory and pharmacologic support. One of the two infants was supported with extracorporeal membrane oxygenation before the diagnosis of congenital myotonic dystrophy was made.

Brachmann-de Lange syndrome with normal IQ

The Brachmann-de Lange syndrome is a disorder with a high degree of clinical variability, generally associated with moderate to severe mental retardation. To date, 7 previous cases of Brachmann-de Lange syndrome with normal intelligence (IQ > 70) have been described. We report the eighth case of Brachmann-de Lange syndrome with normal intelligence. In reviewing the literature, consistent clinical manifestations seen in these 8 patients that are of prognostic value are the absence of significant limb anomalies and birth weight > 2,500 g.

Mosaic 5p tetrasomy

We report on a mildly abnormal 5-year-old girl with seizures, psychomotor retardation, and areas of hyperpigmentation who had a supernumerary marker chromosome in fibroblasts which was identified as an i(5p). To our knowledge, this is the first reported case of tetrasomy 5p. She shares in common some, but not all, manifestations of the dup (5p) syndrome. Cytogenetic analysis of relatives showed that the phenotypically apparently normal mother, maternal grandmother, and a brother of the proband also had a marker chromosome in their lymphocytes which was unrelated to the i(5p).

Cystic sonographic appearance of extralobar pulmonary sequestration

A cystic fetal chest mass showing spontaneous improvement in utero is described. This mass was shown to be an extralobar pulmonary sequestration with associated cystic adenomatoid malformation type 2.

New autosomal recessive syndrome of sparse hair, osteopenia, and mental retardation in Mennonite sisters

We report on 2 Mennonite sisters with a syndrome of sparse hair, osteopenia, mental retardation, minor facial abnormalities, joint laxity, and hypotonia. Their asymptomatic consanguineous parents (inbreeding coefficient F = 1/64) have 6 other offspring, 3 of whom died in infancy of type II osteogenesis imperfecta (OI), and 3 of whom are normal. We analyzed collagens synthesized by cultured fibroblasts from these 2 sisters and their parents and detected no major abnormalities. Results of chromosomal and metabolic evaluations including amino acid analysis of plasma, urine, and hair were unremarkable. A literature search and survey of a computerized syndrome identification database did not disclose an identical phenotype. The sisters bear superficial resemblance to several known syndromes which we excluded on clinical and/or biochemical grounds. We conclude that they represent a new autosomal recessive syndrome, distinct from type II OI and perhaps unique to the Mennonite population or to this particular family.

Clinical variability of type 1 neurofibromatosis: is there a neurofibromatosis-Noonan syndrome?

Detailed clinical, ophthalmological, and molecular studies were performed on a multigeneration family in which there were many subjects with type 1 neurofibromatosis, a common autosomal dominant disorder. Affected family members displayed a wide range of clinical findings including, in two subjects, features seen in Noonan syndrome (triangular facies, downward slanting palpebral fissures, micrognathia, short stature, and learning disability). Subjects have been described previously whose features have overlapped with neurofibromatosis and Noonan syndrome, and it has been suggested that these persons might represent a separate condition. DNA haplotype analysis showed linkage of the neurofibromatosis phenotype seen in this family to the proximal long arm of chromosome 17 in the region where the type 1 neurofibromatosis gene has been mapped. These results imply that the Noonan phenotype seen in some patients with type 1 neurofibromatosis might be the result of variable or variant expression of the neurofibromatosis gene on chromosome 17. The possible role of non-specific factors, such as fetal hypotonia, in producing the neurofibromatosis-Noonan phenotype needs further investigation. The availability of closely linked and intragenic molecular markers for neurofibromatosis could potentially be useful in the diagnosis and characterisation of patients and families with atypical forms of neurofibromatosis.

Chromosomal deletion 4p15.32----p14 in a Treacher Collins syndrome patient: exclusion of the disease locus from and mapping of anonymous DNA sequences to this region

Treacher Collins syndrome is an autosomal dominant condition of bilateral craniofacial abnormalities of structures derived from the first and second branchial arches. A patient with severe manifestations of Treacher Collins syndrome and a de novo chromosomal deletion in region 4p15.32----p14 was identified. Anonymous DNA sequences of loci D4S18, D4S19, D4S20, D4S22, and D4S23 were mapped to the deleted region. DNA probes previously mapped to loci on chromosome 4p (D4S10, D4S15, D4S16, D4S26, D4S35, D4S95, D4S144, RAF1P1, QDPR, and HOX7) were not deleted in this patient. Linkage analysis between the D4S18, D4S23, and QDPR loci and Treacher Collins syndrome in eight families excluded the Treacher Collins syndrome locus from the region of the deletion.

Variant nucleolus organizing regions and the risk of Down syndrome

In order to determine whether nucleolus organizing region (NOR) heteromorphisms of the acrocentric chromosomes could identify individuals at risk for having offspring with trisomy 21, a comparison was made between 43 parents of individuals with Down syndrome and 39 controls. NORs, as visualized by silver staining, were analyzed by mean number per cell, average size, total NOR "mass" per cell (designated mean score per cell) and by mean number of acrocentric chromosome satellite associations per cell. No "double NOR" variants (dNOR) were found in either the control or study group in contrast to observations of others (Jackson-Cook et al. 1985). The risk for having a child with trisomy correlated with a higher frequency of associations and number of NORs per cell, but slightly lower average NOR size. Although these group differences were statistically significant, specific types of NOR variants such as enlarged or dNORs were not associated with the risk of having trisomy 21 offspring. The constancy of NOR mass per cell in our control and study groups indicates that NOR activity remains constant, even though distribution of the rRNA genes (variation in number and size of NORs on the 10 acrocentrics) may vary.

Selection against lethal alleles in females heterozygous for incontinentia pigmenti

Studies of five heterozygous females from three kindreds segregating incontinentia pigmenti indicate that cells expressing the mutation have been eliminated from skin fibroblast cultures and in varying degrees from hematopoietic tissues. Clonal analysis was carried out using G6PD variants and methylation patterns at the HPRT locus. Our results confirm X linkage in these families and suggest that selection against cells expressing mutations that are lethal to males in utero may help ameliorate the deleterious phenotype in carrier females.

Bilateral absence of the ulna in twins as a manifestation of the split hand--split foot deformity

Bilateral absence of the ulna and ulnar rays in twin female infants are described as a manifestation of the split hand--split foot deformity (ectrodactyly). Family history revealed the father had a unilateral split hand. Given the wide variability of expression of this disorder and the availability of prenatal diagnosis, there is a need for obstetricians and pediatricians to recognize parents with this malformation and appreciate the potential for severely affected offspring.

Ocular findings in partial trisomy 3q. A case report and review of the literature

The authors report the ocular findings in a patient with partial trisomy 3 [46, XY-15, der(15), t(3;15) (q26;128) mat] and review the literature on this chromosomal anomaly. The patient's main ocular finding was infantile glaucoma. The patient's mother was phenotypically normal and carried a balanced chromosome translocation. Awareness of the ocular abnormalities associated with partial trisomy syndromes is essential since more children with these syndromes survive today than in the past.

Comparative anatomical analysis of human trisomies 13, 18, and 21: I. The forelimb

Human trisomies 13, 18, and 21 exhibit specific neuromuscular phenotypes (Pettersen and Bersu, '82) which include a high proportion of neuromuscular forelimb variations, many of which are atavistic in nature (de Beer, '58; Barash et al., '79; Aziz, '81a). In order to test the neuromuscular phenotype, examine the atavistic nature, and analyze the developmental delay of the trisomy forearm musculature, we dissected the forelimbs of five trisomy 13, ten trisomy 18, and two trisomy 21 cases. Our dissections compare favorably with the existing published trisomy cases (Opitz et al., '79; Pettersen and Bersu, '82). Additionally, we found significant differences in the stage at which developmental arrest occurred in trisomies 13 and 18 for the pectoral complex, extensor digitorum profundus, and intrinsic hand musculature. Some of these muscles, which occur normally in nonhuman primates (Cihak, '67, '69; Dunlap et al., '85), also appear briefly in normal human ontogeny (Cihak, '72), constituting further evidence for developmental delay in aneuploids. The disproportionately effected limb tissues also lend support to the evidence for some degree of autonomy in their development in normal individuals. Our observations are consistent with Shapiro's amplified developmental instability model ('83). Aneuploids may be viewed as genetic variants from which much may be learned about normal limb development, how aneuploidy affects dysmorphogenesis, and the kind of information which exists on the duplicated (or monosomic) chromosome.

Autism and genetic disorders

The syndrome of autism has been documented as occurring in association with a wide variety of genetic conditions. Autistic patients with a coexistent genetic condition, however, are not behaviorally or developmentally distinct from autistic patients for whom there is no known etiology or associated organic condition. This report reviews the literature linking autistic behavior with genetic conditions. Genetic, neurodevelopmental, and neuropathological findings in three genetic conditions which frequently give rise to autism are presented in detail. On the basis of this review, two hypotheses are supported: autism is a behaviorally defined phenotype which arises from diverse causes of central nervous system (CNS) damage, and the autistic phenotype represents only one point along a continuum of psychological dysfunction resulting from CNS damage. Current theories of genetic influences on brain development are reviewed, with emphasis on the relationships among qualitative, quantitative, and temporal abnormalities of CNS maturation and behavioral dysfunction. A hypothesis of abnormal brain development resulting from dysfunctional myelination is proposed as a potential etiologic factor in autism.

Early manifestations of multiple sulfatase deficiency

We describe two boys, presenting by 1 year of age, with developmental delay from birth, mildly coarse facial features, and hepatomegaly. These clinical features were most suggestive of a mucopolysaccharidosis, particularly MPS II. Biochemical studies, including sulfate incorporation in fibroblasts and lysosomal enzyme analyses in fibroblasts, leukocytes, and serum, showed abnormalities in both sulfatide and mucopolysaccharide metabolism and led to the diagnosis of multiple sulfatase deficiency. With time, both patients developed an ichthyotic rash and profound intellectual deterioration. We conclude that findings in the first year of life in some patients with MSD may closely resemble those in patients with a MPS disorder rather than the late infantile form of metachromatic leukodystrophy, as is classically described. Thus, MSD should be considered in the young patient suspected of having a MPS disorder.

Abnormality of cartilage collagen in a patient with unclassified chondrodystrophy

We have described a previously unrecognized chondrodystrophy characterized by short-limbed dwarfism, blue sclera, severe cardiopulmonary problems, and failure of postnatal growth. The first of two siblings thus affected died at age 6 months following attempted correction of an atrial septal defect. Growth plate cartilage from multiple sites obtained at autopsy showed a marked abnormality of architecture on the light microscopic level. Biochemical studies demonstrated an absence of normal alpha 1(II) collagen in costochondral junction growth plate cartilage and an appearance of the major collagen in a band which comigrates on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with 3 alpha collagen. Cartilage extracted from structural rib appeared to be normal.

Dentinogenesis imperfecta in the Brandywine isolate (DI type III): clinical, radiologic, and scanning electron microscopic studies of the dentition

Teeth of seven patients from the Brandywine isolate who had dentinogenesis imperfecta (DI) type III were evaluated by clinical, radiologic, and scanning electron microscopic techniques. The deciduous and permanent teeth were opalescent, and there was marked attrition. Enamel pitting was present on some permanent teeth. Anterior open bites were found in all persons with complete permanent dentitions. Pulps of developing teeth were larger than normal during early development but rapidly became almost completely obliterated. There was increased constriction at the cementoenamel junctions. While radiolucencies were noted at the apices of teeth which had pulp exposures due to attrition, several patients had similar radiolucencies which could not be attributed to caries or attrition. Scanning electron microscopy showed a significant reduction in the number of dentin tubules on fractured dentin surfaces; calcospherites at the calcification front were either irregularly shaped or absent. A single tooth from a patient with DI type II was studied and had similar abnormalities on scanning electron microscopy, although tubules were easier to find and calcospherites at the calcification front were more regular than in DI type III. The findings in DI type III of enamel pitting, enlarged pulps early in tooth development, and radiolucencies at the apices of teeth without pulp exposures support the hypothesis that DI type II and DI type III are different disorders.

Congenital glaucoma and other ocular abnormalities associated with pericentric inversion of chromosome 11

Pericentric inversion of chromosome 11 occurred in consecutive generations of family members with congenital glaucoma. Affected persons were characterized by unilateral or bilateral congenital glaucoma, bilateral corneal disease, and a lack of appreciable dysmorphism. Previous reports of inversions of chromosome 11 are rare, and no ocular abnormalities have been noted. Chromosomal abnormalities may be the cause of some forms of congenital glaucoma and should be included in the genetic heterogeneity of this disease.

Osteogenesis imperfecta lethal in infancy: case report and scanning electron microscopic studies of the deciduous teeth

Radiologic evaluation of the skeleton and scanning electron microscopic studies of the teeth were performed on an infant boy with a lethal osteogenesis imperfecta (OI) syndrome who died at 10 mo of pneumonia. The skeletal findings included ribs that were focally expanded by fracture calluses, flat vertebral bodies, and wide limb bones. On fractured tooth surfaces, the enamel and dentin were normal as was the dentin calcification front. Although microscopic abnormalities have been noted in teeth from previously reported infants with lethal OI, a few studies also report infants with normal teeth. These differences in dental findings may indicate heterogeneity in OI lethal in infancy. Results of our study indicate that, until the primary biochemical defects in the OI syndromes are elucidated, examination of teeth from other infants with lethal OI and detailed evaluation of other clinical and skeletal features will aid in delineating heterogeneity and variation in expression in lethal OI.

Limb pterygium syndromes: a review and report of eleven patients

Conditions with limb pterygia and congenital contractures were reviewed as part of a study of over 350 infants with arthrogryposis. Emphasis was placed on inheritance and variability of distinct pterygium conditions. Eleven patients with limb pterygia were recognized in our study and are described here. Seven of the 350 patients with congenital contractures had the autosomal recessively inherited multiple pterygium syndrome (Patients 1-7). Three of the seven are sibs, a fourth was born to consanguineous parents, and three were chance isolated cases. These seven had multiple joint webs, unusual finger contractures, syndactyly, rocker bottom feet, ptosis, antimongoloid slant of palpebral fissures, epicanthal folds, highly arched palate, scoliosis, and short stature. There is intrafamilial variability. Three patients from one family had a lethal multiple pterygium syndrome. Two were monozygotic twins. They had webbing and contractures of the elbows, knees, neck, and fingers, calcaneovalgus deformity of the feet, and an unusual facial appearance: hypertelorism, flat nose, antimongoloid slant of palpebral fissures, apparently low-set ears. One had a cleft palate. Internal malformations included: bilateral pulmonary hypoplasia, small heart, absence of the appendix, and attenuation of the ascending and transverse colon. One sporadic case of lethal popliteal pterygium with facial clefts was studied. Multiple anomalies included: ankyloblepharon filiforme adnatum, upslanting palpebral fissures, hypoplasia of nasal cartilages, frenula, clefts into the oropharynx lateral to the mouth, apparently low-set ears with slit-like canals, large popliteal pterygia, syndactyly with fusion of all digits in hands and feet, and hypoplastic labia.

Prenatal diagnosis of congenital adrenal hyperplasia

In patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, the concentrations of the cortisol precursor 17-alpha hydroxyprogesterone (17-OHP) and its metabolite delta 4-androstenedione (delta 4 A) are increased. CAH was diagnosed in twins by measurement of 17-OHP and delta 4 A concentrations in amniotic fluid obtained by amniocentesis from both amniotic cavities at 17 weeks' gestation. Both prenatal karyotypes were 46,XX. Spontaneous labor and delivery of 2 nonviable fetuses with genital masculinization occurred at 26 weeks' gestation. It is concluded that delta 4 A measurement, like 17-OHP quantitation, is valuable in the prenatal diagnosis of CAH; that both methods appear useful in prediction of CAH in twin fetuses; and that abnormal adrenal-mediated masculinization in female CAH is well established before the end of the second trimester.

H-Y antigen and disorders of sexual differentiation

The process of sexual differentiation has been further clarified by the discovery of histocompatibility -Y(H-Y) antigen. A patient with abnormal sexual differentiation whose workup included testing for H-Y antigen is presented. The discovery and clinical applicability of H-Y antigen in intersex patients are presented.