# MOLECULAR GENETICS OF HETEROTAXY

> **NIH NIH K08** · BAYLOR COLLEGE OF MEDICINE · 1994 · $80,920

## Abstract

Visceral heterotaxy is characterized by a variable group of congenital
anomalies that include complex cardiac malformations and situs inversus or
situs ambiguus. These anomalies result from the inability of the embryo to
establish normal left-right asymmetry during development. Different modes
of inheritance in familial heterotaxy suggest that several genes may be
involved. A very large family with X-linked heterotaxy has been reported.
The Applicant proposes to undertake a five year career development program
focused on the isolation and characterization of the gene(s) responsible
for X--linked visceral heterotaxy. As a Pathology Resident the Applicant
acquired a strong interest in the molecular biology of normal and abnormal
development. The Institute for Molecular Genetics at Baylor College of
Medicine provides an environment of general scientific excellence,
experience in training young investigators, and well-recognized
contributions to our understanding of human genetics. The Sponsor has been
particularly successful in isolating and characterizing disease genes on
the X chromosome. The Applicant proposed the study of X-linked heterotaxy
to the Sponsor and together they examined and collected blood on the
majority of family members. In Phase I, initial mapping studies will be
performed utilizing highly polymorphic microsatellite markers. Following
initial mapping of the disease locus, we plan to identify new polymorphic
markers in the region in order to further refine the genetic map. Overlap
cloning will be performed using yeast artificial chromosomes (YACs), and
a search for submicroscopic deletions will be performed. In Phase II, YAC
subclones will be used for the identification of genes from the region.
The expression pattern and sequence analysis of the genes will be examined
in normal individuals and in patients with heterotaxy to determine their
involvement in the pathogenesis of this disease. Further studies will
include the characterization of the structure and function of the disease
gene and its products. Overall, the investigators seek to increase our
basic understanding of the molecular biology of cardiac malformations in
humans and of the development of left-right asymmetry in all vertebrates.

## Key facts

- **NIH application ID:** 2194656
- **Project number:** 1K08HD001078-01
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **SAM.gov UEI:** FXKMA43NTV21
- **Principal Investigator:** BRETT M CASEY
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $80,920
- **Award type:** 1
- **Project period:** 1994-07-01 → 1999-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2194656

## Citation

> US National Institutes of Health, RePORTER application 2194656, MOLECULAR GENETICS OF HETEROTAXY (1K08HD001078-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2194656. Licensed CC0.

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