Non-immune hydrops fetalis is associated with bi-allelic pathogenic variants in the MYB Binding Protein 1a (MYBBP1A) gene.

Non-immune hydrops fetalis (NIHF) is a rare entity characterized by excessive accumulation of fluid within the fetal extravascular compartments and body cavities. Here we present two intrauterine fetal demises with NIHF presenting with oligohydramnios, cystic hygroma, pleural effusion, and generalized hydrops with predominance of subcutaneous edema. The fetuses also presented with ascites, severe and precocious IUGR and skeletal anomalies. Whole exome sequencing was applied in order to screen for a possible genetic cause. The results identified biallelic variants in MYBBP1A in both fetuses. A previous report described another case with a similar phenotype having compound heterozygous variants in the same gene. The protein encoded by MYBBP1A is involved in several cellular processes including the synthesis of ribosomal DNA, the response to nucleolar stress, and tumor suppression. Our functional protein analysis through immunohistochemistry indicates that MYBBP1A is a gene expressed during fetal stages. Altogether, we concluded that MYBBP1A is associated with the development of hydrops fetalis. More cases and further studies are necessary to understand the role of this gene and the mechanism associated with NIHF.

Revisiting the recurrence risk of nonsyndromic cleft lip with or without cleft palate.

Sub-epithelial defects (i.e., discontinuities) of the superior orbicularis oris (OO) muscle appear to be a part of the phenotypic spectrum of cleft lip with or without cleft palate (CL ± P). Analysis of the OO phenotype as a clinical tool is hypothesized to improve familial recurrence risk estimates of CL ± P. Study subjects (n = 3,912) were drawn from 835 families. Occurrences of CL ± P were compared in families with and without members with an OO defect. Empiric recurrence risks were calculated for CL ± P and OO defects among first-degree relatives (FDRs). Risks were compared to published data and/or to other outcomes of this study using chi-square or Fisher's exact tests. In our cohort, the occurrence of CL ± P was significantly increased in families with OO defects versus those without (P < 0.01, OR = 1.74). The total FDR recurrence of isolated OO defects in this cohort is 16.4%; the sibling recurrence is 17.2%. The chance for one or more FDRs of a CL ± P proband to have an OO defect is 11.4%; or 14.7% for a sibling. Conversely, the chance for any FDR of an individual with an OO defect to have CL ± P is 7.3%; or for a sibling, 3.3%; similar to published recurrence risk estimates of nonsyndromic (NS) CL ± P. This study supports sub-epithelial OO muscle defects as being part of the CL ± P spectrum and suggests a modification to recurrence risk estimates of CL ± P by utilizing OO defect information.

Whorl patterns on the lower lip are associated with nonsyndromic cleft lip with or without cleft palate.

Nonsyndromic cleft lip with or without cleft palate (CL/P) is a common birth defect due to both genetic and environmental factors. Whorl lip print patterns are circular grooves on the central upper lip and/or the left and right lower lip. To determine if whorls are more common in families with CL/P than in controls, the Pittsburgh Orofacial Cleft Study collected lip prints from over 450 subjects, that is, individuals with CL/P, their relatives, and unrelated controls-from the U.S., Argentina, and Hungary. Using a narrow definition of lower-lip whorl, the frequency of whorls in the U.S. sample was significantly elevated in cleft individuals and their family members, compared to unrelated controls (14.8% and 13.2% vs. 2.3%; P = 0.003 and 0.001, respectively). Whorls were more frequent in CL/P families from Argentina than in CL/P families from the U.S. or Hungary. If these results are confirmed, whorl lip print patterns could be part of an expanded phenotypic spectrum of nonsyndromic CL/P. As such, they may eventually be useful in a clinical setting, allowing recurrence risk calculations to incorporate individual phenotypic information in addition to family history data.