First trimester ultrasound diagnosis of lethal multiple pterygium syndrome.

OBJECTIVE: Diagnosis of lethal multiple pterygium syndrome in the first trimester of pregnancy. METHODS: A 38-year-old woman attended our ultrasound (US) clinic at 11.2 weeks gestation. She has had two previous stillbirths affected by lethal multiple pterygium syndrome. Transabdominal and transvaginal US were performed and identified a recurrence. Autopsy findings are compared to the fetal US findings. RESULTS: Fetal US showed a markedly increased nuchal translucency, fixed flexion deformities of the elbows and knees bilaterally, cutaneous webs across both elbow joints and absent fetal movements. The patient decided to terminate the pregnancy and a D&C was performed. Pathology of intact fetal parts showed flexion deformity of the right elbow with a cutaneous web, and ulnar deviation of the right wrist. CONCLUSION: Increased nuchal translucency, absent limb movements, multiple joint contractures and cutaneous webs on US allowed the diagnosis of lethal multiple pterygium syndromes in the first trimester of pregnancy.

Population differences in the polyalanine domain and 6 new mutations in HLXB9 in patients with Currarino syndrome.

BACKGROUND: The combination of partial absence of the sacrum, anorectal anomalies, and presacral mass constitutes Currarino syndrome (CS), which is associated with mutations in HLXB9. METHODS: We analyzed 5 CS families and 6 sporadic cases for HLXB9 mutations by direct sequencing. Potentially pathologic expansions of HLXB9 GCC repeats were analyzed in patients, 4 general populations [Chinese, Japanese, Yoruba, and Centre du Etude Polymorphisme Human (CEPH)] from the HapMap project, and 145 healthy Chinese. RESULTS: We identified 6 novel mutations affecting highly conserved residues (Ser185X, Trp215X, Ala26fs, Ala75fs, Met1Ile, and Arg273Cys). GCC allele and genotype distributions showed marked statistically significant differences. (GCC)11 was the most common allele overall; its frequency ranged from 90% in CEPH to 68% in Yoruba and 50% in Chinese and Japanese populations. (GCC)9 was almost as common as (GCC)11 in Chinese and Japanese populations, whereas its frequency was <10% in Yoruba and CEPH populations. The Yoruba population had the highest frequency of the largest alleles [(GCC)12 and (GCC)13], which were almost absent in the other groups. CONCLUSIONS: Lack of HLXB9 mutations in some patients and the presence of variable phenotypes suggest DNA alterations in HLXB9 noncoding regions and/or in other genes encoding HLXB9 regulatory molecules or protein partners. If HLXB9, like other homeobox genes, has a threshold beyond which triplet expansions are pathologic, those populations enriched with larger alleles would be at a higher risk. The data illustrate the importance of ethnicity adjustment if these polymorphic markers are to be used in association studies.