Hemoglobina

Am. J. Hum. Genet. 56:745-752, 1995

Recommendations for Standardized Human
Pedigree Nomenclature
Robin L. Bennett,' Kathryn A. Steinhaus,5 Stefanie B. Uhrich, Corrine K. O'Sullivan,' Robert G. Resta,
Debra Lochner-Doyle,4 Dorene S. Markel,6 Victoria Vincent,7 and Jan Hamanishi2
'Division of Medical Genetics and 2Department of Obstetrics and Gynecology, University of Washington MedicalCenter, and 3Center for Perinatal Studies,
Swedish Medical Center, and Genetics Services Center, Department of Health, Seattle; 'Division of Human Genetics, University of California,
Irvine, Orange; 6Human Genome Center, University of Michigan, Ann Arbor, and 7Division of Genetics, University of South Carolina School
of Medicine, Columbia

Summary
The construction of an accurate family pedigreeis a fundamental component of a clinical genetic evaluation and of
human genetic research. Previous surveys of genetic coun-

selors and human genetic publications have demonstrated
significant inconsistencies in the usage of common pedigree
symbols representing situations such as pregnancy, termination of pregnancy, miscarriage, and adoption, as well
as less common scenarios such aspregnancies conceived
through assisted reproductive technologies. The Pedigree
Standardization Task Force (PSTF) was organized through
the Professional Issues Committee of the National Society
of Genetic Counselors, to establish recommendations for
universal standards in human pedigree nomenclature. Nomenclature was chosen based on current usage, consistency among symbols, computer compatibility,and the
adaptability of symbols to reflect the rapid technical advances in human genetics. Preliminary recommendations
were presented for review at three national meetings of
human genetic professionals and sent to >100 human
genetic professionals for review. On the basis of this review
process, the recommendations of the PSTF for standardized human pedigree nomenclature are presented here. Byincorporating these recommendations into medical genetics professional training programs, board examinations,
genetic publications, and pedigree software, the adoption
of uniform pedigree nomenclature can begin. Usage of
standardized pedigree nomenclature will reduce the
chances for incorrect interpretation of patient and family
medical and genetic information. It may also improve thequality of patient care provided by genetic professionals
and facilitate communication between researchers involved with genetic family studies.

Received October 3, 1994; accepted for publication November 28,
1994.
Address for correspondence and reprints: Robin L. Bennett, Medical
Genetics, RG-25, University of Washington Medical Center, Seattle, WA
98195.
X) 1995 by The American Society ofHuman Genetics. All rights reserved.
0002-9297/95/5603-0025$02.00

Introduction

The construction of an accurate family pedigree is fundamental to the provision of clinical genetic services and
serves as an informational framework for human genetic
research. Review of a family pedigree aids the clinician in
diagnosis, helps establish the pattern of inheritance, and
assists in identifyingpersons at risk. The pedigree also
serves as a reference of social and biological relationships
to alert the clinician to issues of blended families, adoption,
deaths, pregnancy termination, and pregnancies conceived
by assisted reproductive technologies. Correct interpretation of family pedigrees is essential for human genetic research and is particularly challenging when reviewing pedigreesdiagrammed within professional publications or
when research teams collaborate to study large families.
Pedigree analysis also facilitates the identification of disorders where genetic mechanisms such as anticipation, mitochondrial inheritance, X-linked or dominant homozygous
lethality, and differential age at onset, based on the sex of
the transmitting individual, are factors.
Although one...