11 / 99
W
HITTLE
M
ET
AL
.
98
r
Ev
a
SSoC
m
ED
B
raS
2014; 60(2):98-102
GuidElinES in FoCuS
Hereditary polycystic kidney disease: genetic diagnosis and
counseling
D
OENÇA
POLICÍSTICA
RENAL
HEREDITÁRIA
:
DIAGNÓSTICO
GENÉTICO
E
ACONSELHAMENTO
Participants:
M
ARTIN
W
HITTLE
; R
ICARDO
S
IMÕES
Sociedade Brasileira de Genética Médica
Final preparation:
N
OVEMBER
20
TH
, 2012
Conflict of interest:
N
ONE
http://dx.doi.org/10.1590/1806-9282.60.01.004D
ESCRIPTION OF
THE
EVIDENCE COLLECTION METHOD
The literature review of scientiic articles in this guide-
line was held in the databases Medline, Cochrane and
SciELO. The search for evidence came from actual cli-
nical scenarios and used keywords (MeSH terms) grou-
ped in the following syntax: adult dominant polycystic
kidney disease; adult recessive polycystic kidney disea-
se; PKD mutation; PKDH1 mutation; renal cystic disea-
se; polycystin; renal ultrassonography; renal transplan-
tation; ibrocystin; congenital hepatic ibrosis; biliary
dysgenesis; liver cystic disease; end-stage renal disease;
linkage analysis.
D
EGREE
OF
RECOMMENDATION
AND
STRENGTH
OF
EVIDENCE
A:
Experimental or observational studies of higher con-
sistency.
B:
Experimental or observational studies of lower con-
sistency.
C:
Case reports (non-controlled studies).
D:
Opinions without critical evaluation, based on con-
sensus, physiological studies, or animal models.
Objectives:
to present the main scientiic information
linked to acquired clinical experience and related to diag-
nosis and genetic counseling in polycystic kidney disea-
se (hereditary).
I
NTRODUCTION
The hereditary polycystic kidney disease is deined as au-
tosomal recessive polycystic kidney disease (ARPKD) and
autosomal dominant polycystic kidney disease (Adpkd).
These two diseases must be distinguished from other he-
reditary or non-hereditary conditions presenting renal
cysts. The hereditary polycystic kidney disease is impor-
tant because it is relatively common. Adpkd is one of the
most common monogenic diseases, with an incidence of
1 in 700 individuals and accounts for 5% of patients re-
quiring hemodialysis or kidney transplantation (
B
).
2
AR-
PKD is rarer, with an incidence of 1 in 20,000 individuals
(
B
).
2
I
N
PRENATAL
AND
NEONATAL
CONTEXT
,
ULTRASONOGRAPHY
IS
SUFFICIENT
TO
CONFIRM
THE
CLINICAL
DIAGNOSIS
OF
ARPKD
IN
A
PATIENT
?
In ARPKD, renal ultrasound abnormalities are detecta-
ble from the 20
th
week of pregnancy, or perhaps from the
13
th
week of pregnancy when there is an established diag-
nosis in an affected sibling. However, this applies to 40%
of the affected patients that have a more severe form of
the disease. In this subgroup, the ultrasound reveals en-
larged bilateral hyperechogenic kidneys, with or without
cysts associated with oligohydramnios (
B
).
2
Before focusing on this nephropathy, renal tract ab-
normalities (obstructive cystic dysplasia and multicystic
dysplastic kidney) should be excluded. Other hereditary
nephropathies (e.g., Bardet-Biedl syndrome) leading to
this clinical picture are associated with other anomalies,
which set them apart (
C
).
3
The most important differen-
tial diagnosis is an early presentation of Adpkd. For this
reason, it is essential that both parents undergo renal
ultrasounds to diagnose the disease. A pregnant woman
with fetus affected by Adpkd usually has a normal amnio-
tic luid volume. Patients in this subgroup (40%) develop
Potter sequence and die of respiratory failure shortly after
birth. Other patients affected with milder ARPKD (60%)
do not show conclusive ultrasound signs and can survi-
ve for more than three decades.
Recommendation
Ultrasonography is the irst investigation applied in fe-
tuses and neonates with suspected ARPKD. In addition,
enlarged and hyperechoic kidneys are common indings
on routine ultrasound examinations in this context. It is
essential, subsequently, to assess the patient’s family back-
SCIELO BOOK.indb 98
4/22/14 4:35 PM